For me it's not hatred, but it's annoying that wherever you go on the internet you get inundated with "america this" and "america that" when it's not relevant to what you're looking for. The only way to escape this is to seek the parts that aren't in english and those tend to be less active for specific communities.
You mean in the picture? Sure, they "asked for clarification" and got a snarky response. They didn't ask for clarification out of nowhere, they confused themselves with their own assumptions while forgetting that other countries exist.
How is it mean-spirited? If anything the person making the assumption about the poster's country and implicitly accusing them of selling alcohol to someone under the drinking age is mean-spirited and unkind.
I'm sorry to tell you it is not lemmy that hates America, it is the rest of the world.
Americans are so full of themselves that they think their problems are world problems and go posting them everywhere like we give a fck.
They tell the rest of the world what to do/think while they don't have their own shit in order. They are indoctrinated into thinking they live in the best country while actually America is in real bad shape.
Yet they are so quickly offended that they have million dollar lawsuits when someone burns their tongue from buying hot coffee.
They are so easily shocked by someone driving 140km/h while the rest of us just shifts to 4th gear.
In our view Americans are prude, weak minded, short minded and annoyingly loud. It is like they stopped developing at some point and act like attention seeking brats.
As a non-American, I get what you say, but I recognise most of those things as stereotypes or examples of extremes.
I'm not a fan of the current state of the US as a whole but my guess is that the average American is as fine -or as bad- as an average local in my own country (both have stereotypes and we can laugh about that). Be it with some different cultural norms.
Some things might surprise one another but I try not to confuse the loudmouths and extreme depictions in the media with the whole population.