Is the term "USians" just something UKians started using recently?

"USians" makes it sound like you are talking down to people

It's right there in the comment...

Americans

Okay, there are two continents called that, though.

Fun fact: This actually depends on which part of the world you're from. In the US, we're taught that there are seven continents. Some countries teach that there are fewer. For examples:

• Some regions teach that "Eurasia" is one continent. In the US, we're taught that Europe and Asia are two separate continents.
• Some regions teach that "North America" and "South America" are one single continent called "America." I think this one seems to cause a lot of confusion across various cultures. If I understand correctly, some of these cultures recognize North, Central, and South America as subdivisions of the continent "America." Maybe this confusion is what leads to the creation of new terms like "USians."

I've never heard of an education system that teaches "two continents called America". That's fascinating. "This one is called America. This other one is also called America. However, they are not one continent; they are two continents with the same name." It seems like a confusing concept, IMO, but I suppose every culture has its quirks.

Appending a suffix like "ians" to an acronym is also an interesting concept. I'm not confident enough in my grammar skills enough to comment on whether it's (in)correct, but it's interesting to see language evolve. How is "USians" pronounced? Is it "U-S-ians"?

Okay, there are two continents called that, though. The country being talked about doesnt even cover half of one.

Ngl, a fine start to an argument - truly I mean that. However, keep going: by your logic, trans women are not real women.

Think about it: trans women choose to be called by the pronoun "she". But you don't want to, so you will instead call them your choice of pronoun "he".

Americans can be silly, yes. But the terms used to describe anyone at all reflects more upon the users than to the group to whom they aim to refer to.