See, you can do things to prevent a union, but you can't prevent it from attempting to happen.
Yeah I think you should be able to fire anyone for any reason. This violates freedom of association.
YTou can fire someone for any reason at any time.
You just can't say what the real reason is. Like, seriously. You can fire someone for being a black homosexual toga dancer, but you just have to say their performance has slipped in the past 2 and a half hours.
Like seriously, it's not hard.
Unless they have a union. Then it becomes way harder.