The world, exactly like the Internet, does not end at the US borders.
And yep, even though many US citizens seem to be on the verge of slicing each other throats, it doesn't mean the rest of the world should behave the same. Lemmy users should still be able to discuss freely even between people of varying opinions, or even of completely opposite opinions.
It's funny, cuz i remember tons of responses like that when i used Reddit, too. But the onslaught was often worse cuz the larger user base had more power to bombard you with insults about how wrong you are, and give you 49 downvotes in 10 minutes just cuz you give some criticisms about a popular game you didn't happen to enjoy and forgot to add reluctant praise to ("i recognize it's a great game and well made, but its just not for me sad face.")
I think this is just a bad part of the internet, in general. Similar things would even happen in AOL chatrooms if someone voiced a disliked opinion, I remember Diamond chat would get crazy
To be fair it kinda is a bad part of even real world communities. Try going to a biker bar, animecon or any other community and saying "Gosh darn I don't like ____". Best case people would look at you funny and leave, worst - you getting a knuckle sandwich