"I use my judgement" is the cop out. Crazygringo asked what the underlying principle is to provide justification for an otherwise arbitrary-sounding rule. The underlying principle you provide isn't actually an underlying principle at all - it's just pushing the arbitrary-sounding rule one level up.

You might as well just say "I use my judgement" as a (non-)answer to his original question.

Your suggestion that people asking for a (moral/political) philosophical justification of a law is a "cop-out" is simply anti-intellectual. You might not carefully think through your views, but some of us (i.e. crazygringo) at least try to. I know the idea is a little threatening (you run the risk of discovering your views are wrong, omfg!) and suggests possible tribal disloyalty, but please recognize that crazygringo basically agrees with you [1] and is just trying to understand intellectually why.

[1] I'm interpreting this from the first and last lines of his post.

I do carefully think through a lot of things, I just don't end up with the conclusion that companies should be free to form cartels while passing "right to work" laws that hobble unions.

I'm ok with you disagreeing with me and/or insulting me for not playing the society game by your rules.

I have no idea why you are arguing against a conclusion that neither crazygringo nor I expressed. I have no idea why you think we disagreed with you - crazygringo explicitly agreed with you and I never expressed an opinion.

I've discovered that I learn far more when I treat questions I have no answer for as an opportunity to learn than when I treat it as an insult and a straw man argument.