Yes, you can totally fire them. These aren't labor issues (i.e. working conditions or unionization which might provide some protection), and this isn't politica

Yes, you can totally fire them. These aren't labor issues (i.e. working conditions or unionization which might provide some protection), and this isn't political protest /outside/ work. This is no different than, "I refuse to work in Java because I hate it," and you get fired.