There is actually a fascinating bit of psychology theory behind that one.
You see, in the United States, men are generally expected to curb their anger. Hide it, dilute it. This has had the odd side effect of many people associating a man being angry with a man being honest for once.
Its illogical as hell, but if someone is tired of having to curb themselves to meet societies norms, someone defying them angrily can be… inspiring in a rather vulgar fashion.
And that, ultimately, is what Trumpian politics is. It is a backlash against the progress made in recent decades by various civil rights and politically correct measures.