I kind of understand this if the questions are mean-spirited. But some troll questions are just meant to be amusing/humorous and aren't meant to be taken seriously. If it's not harming anyone then I don't see why they should care about it.
Personally, after scrolling through so many relationship and penis questions, sometimes it's a relief to see something different.
My thing is. who are they to decipher what are troll qiestions? People say pretty much everything is a troll question and everyone is a troll when sometimes that just isn't the case and people are dead serious so they have no right to remove them... Some people are really seeking help and they can't tell trolls fro, meal situations apart 😒
Because if they permitted troll comments/questions, the trolling would be even more prevalent around here. I can't imagine an advice site that's comprised of 90% as one that would be particularly popular or successful.
Your opinion of "harm" probably differs from the opinion of others. Most troll are annoying to the point that some users leave this site. What's difficult to understand: a 24 year old guy who derives joy from being annoying to other people is pathetic.