This thread shows how impossible it is to be a ref.
Generally we get mad if the refs react to the 2nd incident. Here Draymond committed the first dirty play and was punished for it and people are still mad. They didn't punish Mitchell as much for retaliating.
NBA players (and especially Draymond) live on the edge of the rule book which makes it pretty impossible
I do think scoring and the game in general is easier for top players. Improved spacing, reduced defensive rules, more protection for shooters. It's just a lot lot easier to be a perimeter player now that it was even in Kobe's day.