Have you, at any point, thought "This seems like such a niche^, marginal idea, people will never use it coz it just seems outright unnecessary and useless, perhaps I should just be doing something else"? How did you answer it for yourself while you were working on it? How do you feel about it now after you've spent some time/money and shut it down, in return of getting the experience that you've got?

I'm not trying to berate your project in any way by the way, shipping a real project is one of the highest values any of us can uphold, but the above thought about [random-niche-idea-here] is what keeps me (and I presume many others) from actually executing.

^ "niche" not as in "a specialized but profitable corner of the market.", but as in "something that's sucked out of thumb and doesn't seem to have a wide practical need/use", sorry couldn't find a good word to describe that.