alt Hacker NewsThere are billions of people in the world. 50k is 0.005% of a billion, so 1 in 20000. This is the reason I think money/market-motivated thinking, that often leaves people pursuing something they're not especially personally enthusiastic about, is wrong for most people. If your goal is to be a billion dollar grow-fast multinational company, okay, but if your goal is to just live a comfortable life and create something neat - then it's much better to sell a niche thing that you enjoy, than a mass market thing you just want to make a buck off of.
For a gaming example of this, it's often cited somehow as a negative that "only" 14% of games released on Steam will earn more than $50k. The way I look at that figure is that there are now about 20,000+ games being released on Steam per year, and so that means that each year some 2,800 games will go on to earn $50k+ - that's more than 7 games a day, every single day. I'm a pretty big gamer, but don't think I could list 2,800 games in total across all systems and my entire life - yet that is how many new games go on to earn $50k+ on Steam every single year.
For most things, there aren't 50k reachable, aware, motivated, solvent buyers. Making enough people aware of your existence may be more expensive than the total profits made from your endeavour.
I am only pointing this out because I know people who would hear the first part of your comment and get their egos attached to an idea since they interpret it as 'there are billions of people, so I only need a tiny percentage, there is no bad idea, only bad execution' and lose years of their lives pursuing something where odds are stacked against them, if there were any odds in the first place. I'd urge people instead to also hear the 2nd part of your comment, and take it as 'experiment with many niche things, there are some that land and land well'.