What if the person was a member of an anti-vaccination group? Or a racist group?

This person is sending very bad signals about himself, signals most people will not ignore. But they don't actually say anything about his job performance (in this hypothetical case)!

Incredible, I'm very lucky he is probably severely undervalued in the labour market. By hiring him I am getting a bargain.

I attach no metaphysical badness to him getting paid by me because a boycott on hiring people who use their money for ill is impossible to enforce. Someone else will profit from hiring him (and I have no guarantees this person who profits won't use the difference to work against things I value).

All I am getting is a service for my money, I have no responsibility for what he actually does with the money, I mean I do usually think on ethical issues if we are moral agents.