First he treats two very old people very badly,
”Woe to a man who is seventy, yet prostrates himself before this thing which was made only today.” and “May the breath of such a woman be blasted! To think that one so old prostrates herself before a god who is only one day old.”
Sure he was "right" but there is such a thing as respect for older people that is found in the tradition. When he sets the scene for his father but destroying his idols, he does the same thing. At that point, Avraham was introducing or reintroducing the concept, of monotheism into the world. Was the best and most moral way to do it, acting like a college sophomore?
It is so easy to treat other people as fools. We (definitely including me) do it all the time, yet is it the best way “to spread the gospel” (inappropriate metaphor?). There are other Midrashim about how many people Avraham and Sarah converted. Maybe Sarah’s influence improved his understanding and respect for others.