How about people who eat meat? Or vote for the other party - the one you don't like? Are you trying to hire people who are morally compatible with you on every single question? That's gonna be rough hiring.
Even the weapons industry is a tough one. The knee jerk reaction says it's immoral to work for them. But after contemplating - if the U.S (or Europe, or anyone else) doesn't have an advanced military it will be taken over by its enemies (Chinese, Russians etc). Yes, the fact that "they" build their own militaries for the exact same reason is tragic. But if the U.S just dismantled it's arms industries what do you think would happen in a few decades?