"Do these people exist?"

This is spot on. When you hear NetBSD developers arguing about proposals (or commits, ex post facto, like here), there is often mention of "users". But these are mostly fictional.

I think it's safe to say most NetBSD users are comfortable working with C.

I reckon it's not much different with OpenBSD: most changes they make are for the benefit of the developers themselves, to suit personal preferences, than for the benefit of other "users". (And that's perfectly acceptable, I think.) Of course, these changes can benefit users beyond simply those who make them and those who approve them, but those users are not the ones driving the changes.