I notice this especially with my Norwegian learning. People are rude, call me names, or make fun of me on Reddit for using the wrong word or “en” vs “et” or using a direct translation because I don’t know how they say it in Norwegian, like saying somethng like «Ingen av bedriften din!» instead of «Dette er ikke din sak» (according to the casual version of Bing Translate) whereas a Norwegian-speaking Fediverse member would just say something like “You’re doing good, but it’s actually _____.”
I’m pretty sure the ratio of rude people in the entire user base isn’t the same when comparing the two platforms, so that plays a role too. However, I think it’s mostly a numbers game. Even if that ratio was the same, a bigger platform automatically means that you’re going to bump into a lot of rude people there. Think of it like this: If the ratio is just just 1%, that’s 1 in a small place and 100 in a big one.
On top of that, people tend to remember negative encounters very well. Even if you got only 1 nasty comment, it’s going to sting. If you got 100 comments like that, you’ll feel like the whole world is out there to get you. The human mind has this strange bias towards negative reactions.