This is absolutely true. You'll come to love the tools you make (and hopefully other people will too!)
I'd love to write my own text editor, though I imagine that I'd want a whole lot more features than my "optimal" music player (probably some sort of autocomplete, syntax checking, heck just make it a full-blown multi-language IDE).
By random coincidence, I've been writing (and using for the past year) my own super minimalist ncurses music player (https://github.com/spotco/ScrapePlayerDESKTOP , one python file, powered by sox and most likely only works on OSX).
My needs were definitely very different from the OP (I just wanted the ability to play music by all folder, and all folder recursively), but it's really interesting to see other people's versions of their "optimal" player.
HTML/JS insertion wasn't anything I ever intended for, but it turned out to be a really neat feature/bug.
You can do almost anything by inserting a little JS, like inserting an image, changing thread background or styling text (something that would normally be done in bbcode/etc).
And among other things, if you don't like a thread, you can "close" it with <!-- or redirect it elsewhere.
I think this would be a really interesting feature on a "real" message board (albeit with some constraints)
android: https://play.google.com/store/apps/details?id=com.spotcos.Sp...