I disagree with that. If you make what you want, you at least have one user. If you make what you think other people want, you might end up with zero!

Nobody wanted an open-source Unix-like OS, a keyboardless touch screen with third-party apps, a mini hard drive with a display and headphone jack tacked on, maps that could be infinitely panned instead of clicking arrows, etc. But they ended up being some of the defining products of our time.

The worst case of working on your own thing is that you make something nobody else wants. The worst case of working on something you think other people want is that nobody wants it, and you get burned out.