> if the nix community is that against me taking money from the military

As far as I understand it, the objection would be if

  - you were simultaneously a key person in Nix, like a release manager
  - your company officially sponsored events that associated Nix with military
  - several of your employees were active contributors to core parts of Nix

I think the last one might not even be a big issue, or at least it might not blow up.

Surely, the usage of Nix in any domain is a free choice. You can't really police that anyways.