I haven’t had any poor experiences online in Animal Crossing, no. I did have bad experiences on other games, however. Animal Crossing is such a nice game and I can’t imagine anyone being a jerk on that game. The people that are, are usually young kids trying to have some fun.
I think the community changes depending on where you find people. People on Facebook in general are usually a lot meaner. Those you find on forums are typically much nicer. I think if anyone has encountered a troll or had a bad experience online on this game, it was probably just a bad part of the community. It doesn’t make the whole community bad. The people on this forum are pretty nice and I’d assume it’s highly unlikely you’d have a poor experience here.