Yes, it would have been nice to see Hermione really start to fulfill her badass potential. But this was a pretty good place to end the story.
Trolls are bald, and I don’t know if they have fingernails. If they do, then there’s probably a set length up to which troll nails will regenerate without further growth.
Our culture typically presents rationality as opposed to emotion; I believe that a disproportionate number of misanthropes are drawn to rationality for that reason.
However, logic is meaningless without having an underlying goal, and goals are generally determined by one’s emotions. What are your goals?
I find that thinking of other people as inferior or irrational is not particularly helpful in accomplishing my objectives. I feel less stress and make more progress by recognizing that other people have different goals than I do.
It is possible to get others (even “irrational” others) to help you accomplish your goals by offering to help them with theirs.