I’ve heard of bad hygiene being more of an issue at furcons and anime conventions tbh.
I think the quirkiness comes from the fact that a lot of people in the fandom don’t really fit into traditional spaces and/or don’t conform to usual societal norms. You see this with the furry fandom as well. And because of that you end up with a group of individuals who tend to be sort of outcasts. And outcasts, for various reasons, don't usually have the best social upbringing which tends to lead to some awkwardness or social difficulties. Obviously none of that is a hard and fast rule or anything, there’s always going to be folks that deviate. This is all just observations I’ve noticed from personal experience and being in the MLP and furry fandom for a long time. And I’m absolutely not saying any of that is bad, if anything I think it’s great to see communities like MLP that allow us more weird folk to band together .