I can't speak for all programmers, but as a game developer myself, my take is: your very job as a game developer, above all, is to find the fun. This is especially prudent if you're making a game for other programmers. If I already had a solid idea in my head for what would be an amazingly fun programming-oriented game, I would... program it myself. I don't have such a concept in mind. I believe finding those concepts is something you have to find out by tinkering with ideas, building prototypes, working out the implementation details and seeing what you yourself enjoy.

I don't disagree with any of that =)

It's what I've been doing, I'm asking what I'm asking to see if it surfaces anything that I've been missing / not thinking about and trying to work out what people would see as table stakes

In the same way that I know that playtesting reveals flaws and gaps in my design and thinking, this is a earlier version of that process that has in my experience helped me when building non-game related things

It may very much be the case that this is not the kind of thing that I should do when focused on building a game, but I don't think it hurts to ask