I know a few dozen people who are looking for a 'good startup idea' and are seemingly held back from starting up only because they don't have an idea.
Which is curious, because there is a notion floating around that ideas are not important, or at least not very important wrt startups, and execution is all that matters. In other words you can have a so-so idea but execute brilliantly and succeed.
This is a slippery enough concept that nailing down exactly what is meant is difficult, leave alone arguing against it. But I've consistently encountered situations where talented, hardworking people say they have trouble coming up with startup ideas,
The other day I met a friend who I haven't seen for years, and since like everyone who is halfway technically competent, he is also "planning a startup". One of the questions he asked me was "So, do you have any decent ideas for a startup?" My answer "Sure, I have a few dozen" seemed to surprise him. I suspect that 'I have plenty of ideas, sure' is a somewhat unusual answer amongst would be startup folks (who can also code).
So this friend is a sharp dev, who can build anything he can conceive, has worked in startups, and still hesitates wrt starting his own company because he doesn't 'have a good idea'.
Yet another friend, ex dev, who works as a manager in a (time and materials) software services company, tweeted the other day, about his (mild) frustration with an 'agile methodology' process bottleneck, and another friend who is an immensely successful entrepreneur, wrote back "Quit now. Life's too short for this nonsense. build something, give it your best shot and you'll love every minute of it.." And my manager friend replied (I am not doing a startup because)"I don't have a good idea yet".
A third friend, very talented, with massive experience in business consulting, able to spot inefficiencies in half a dozen industries, still went into a loop of "What is a good idea for a startup?" and stayed there for a few weeks.
When you see something repeat three times, it is probably worth investigating what the underlying dynamic is.
Paul Graham in his recent essay "How to get Startup Ideas", says,
"The very best startup ideas tend to have three things in common: they're something the founders themselves want, that they themselves can build, and that few others realize are worth doing."
Turning these into questions, an alternative to asking yourself "What is a good idea I can build a startup on?" is to ask yourself
(a) What do you(personally) want (to exist in the world)?
(b) Can you build (the answer to the previous question)
(c) Do other people see/are other people working on the same opportunity?
These are easier questions to answer than 'What is a good idea for us to build a startup around?'. So how come people aren't attempting to answer them?
The rest of the essay deals with characteristics of good ideas vs mediocre ones, and how to select between multiple ideas and so on. (the whole essay is well worth reading).
Now let's look at someone who thinks very differently.
Paras Chopra, CEO of Wingify, is pulling in millions of dollars, from an office in India with a very small team, at an age where most of us are doing entry level jobs in IBM or Infosys or wherever. He found out the hard way that building 'cool' things don't necessarily bring in the money, so he decided to explicitly focus on making money. And he did (make tonnes of money).
Paras, like PG, is a doer, not a self help guru. I am fairly allergic to self help pablum by people whose job is selling self help pablum in the form of books or conferences (hence my dismissal of the whole "Lean Startup" (TM) idea, which is mostly tonnes of anecdotes wrapped around a sliver of a 'mother hood and apple pie" homily (hello 'agile'!). So yeah, I don't really believe in "set up a landing page and fool people into leaving their emails so you can spam them" type approaches.
Paras wrote a trio of blog posts illuminating his philosophy -- "Sorry your "cool" webapp is probably not going to make money", "How to find startup ideas that make money", and "Validate your startup idea by asking three simple questions"
Again his advice can be turned into the 'questions to ask yourself' format.
from his second essay, a more fruitful set of questions to ask yourself (than "What is a good startup idea?")
(a) What product is already making money for other people?
(b) Do you find this product (area) interesting /aligned with your skill set?
(c) What is a niche within the product area where you can launch a competing/disruptive product?
Again, these questions are more focussed, and easier to answer, than the overarching "What is a good idea for a startup"?
It is way easier to answer "What product is already making money for other people?" or "What do you(personally) want (to exist in the world)?" than "What is a startup idea"?
If so, and spending a day or two with these questions (and other 'how to do it' advice from people who have already walked this path) would generate half a dozen ideas, why do people still agonize over finding the right idea?
I think the real problem is more subtle. (Putting on my cynical hat) I think most people going around with "What is a good startup idea?" have no more intention of following through if they did get one, than do people who keep saying "I am going to write a novel (someday)" . I don't think serious writers (or even wannabe writers) greet each other with "So, do you have any nice ideas yet for a novel?". They might have rough drafts of their next novel, but I doubt they spend time agonizing over 'good ideas' over beer.
Suppose you did get that 'perfect idea'. Are you really going to resign your job? And explain to your spouse, inlaws and kids, that you gave up a perfectly good job for an uncertain shot at changing the world? Then work insane hours and get into unknown territory like staffing, fund raising etc?
Isn't it easier to just talk about it? Say "I would be attempting a startup if only I had a good idea"? The easiest way to never startup is to dismiss any embryonic idea with some form of "Yes, but ..."
My rather cynical conclusion is that a "good startup idea", for most people, is something to think about occasionally, and talk about, and not really be executed upon. Which is perfectly fine, of course.
None of this is to argue that a startup is somehow a more noble endeavour than holding down a BigCorp job, or consulting. I also suspect that startups are started either by people who've never held down a job (and don't want to), like the mythical Stanford students in their dorm, or by people who've had enough of the corporate bullshit that permeates most BigCo jobs, and decide to do a lifetime's work in n years and raise their 'Fuck You money', so they don't have to work anymore. People who are ok with their jobs don't (and probably shouldn't) try.
So why don't I do a startup? See above, tweak the details a bit.
All this applies to me just as to everyone else. My 'problem' with 'starting up' is not a lack of ideas. I don't have any trouble coming up with a few dozen ideas whenever I want to. I am a good enough programmer that I can build most things I can think of.
I don't want to start a company all by myself (this could change). Most people I'd like to work with live in the USA, and I have no plans to live there, ever. I also don't want to work on technically trivial projects (I'd be very unhappy working on a Groupon clone, or doing Ruby on Rails consulting say). Meanwhile consulting on machine learning gives me my 'tackle hard problems' fix. What's not to like?
Are any of these insormountable obstacles? Not at all. I just choose to use these 'reasons' as excuses to go on doing what I do(vs actually living up to potential, what a scary thought ;)) .
So I'm stuck, just like most other people. And I know why I'm stuck. I just try not to fool myself too much ;)