> created solely for myself; I never had the intention of making it [...] mainstream

This is a habit I picked up from two people I respect greatly as programmers; Casey Muratori and Jonathan Blow.

Those guys both built their own little lands; Jon went as far as building a new language, a 3D game engine in that language, and has multiple game titles in-flight in the engine.

I have a handful of projects that are similar in spirit. I'm largely the only, and target, user of these projects. It's joyful to work in an environment you control completely. No deadlines, no feature requests, no support tickets, no garbage collector, no language runtime .. just me and the OS having a party.