Fair enough; so we agree to disagree.
Now while manners tell us something, they are hardly definitive, particularly in a low calling like politics.
And I assert that it is the media, addicted to political correctness as a cudgel to force conformity, rather than the values of average people, that define what are/are not acceptable traits. In my judgement, nice guys always finish last. Suggest Trump adopt the succinct words of Roman Senator Lucius Accius: “Let them(Carthage)hate; as long they fear”.
I think you're making the same analytical error as Trump. He has run his primary campaign as if how you win is unimportant - that insulting and tearing down other candidates in a primary is just as good as simply out-shining them. And it isn't, because you will eventually need them as allies for the greater fight to come if you hope to win. Trump has been systematically insulting/offending the very people he will need after the Convention. It is utter foolishness.
Rome could not defeat Carthage in the Second Punic War until they converted the Numidians to allies, depriving Hannibal of his advantage in cavalry.
Had it been Donald Trump instead of Scipio, he would have told Masinissa that his wife was fat, his kids were ugly, and the food he served was gross. And he'd have gotten his ass kicked at Zama.