1) Too many languages don't have native enumeration and set types to make a clean and elegant solution even possible.

2) Too many developers don't know how to do it, even if they use a language where it would be possible; some because they couldn't figure it out, but most probably just out of rote habit.

And yeah, sure, not quite everyone. But most, AFAICS. And I haven't seen any coherent argument against it from anyone actively claiming it's bad (Idunno, are there any besides you?), so feel free to try again and contribute something more convincing than your previous attempt.