Why does Bill take shit from Micah?

So we all know Bill is a pretty angry feller, he gets mad easily and can yell at you or even fight you just because he feels like it. Yet, each time Micah jokes about him being dumb or straight up insults him he doesn't do anything about it and doesn't even say much to him. It's pretty weird imo since Bill is the bigger man out of these two and he would most likely kick his ass if he wanted to. Why is he such a pushover when it comes to Micah? Is he afraid of him? What do y'all think?