Find two more selfhosters and they will criticize both of us!

Absolutely. However I'd argue that some BSD variant is at the other end, not Gentoo, so there's at least some critics to you ;).

I'm running proxmox and (mostly) Debian on top of that, and I'm sure that there's someone thinking I'm doing things the wrong way.

With Windows Servers I think the bigger problem is that there's way less people running things on top of it, so there's less knowledge about problems and solving them. However, many of us are on corporate IT jobs too and thus have to work with Windows, so that might somewhat cancel out the difference in popularity.