Saying "LOL... it makes no sense" about the label self-applied by people in a culture you aren't familiar with doesn't add anything to the conversation, and it comes across as rude and dismissive. You don't need to type everything that comes into your head into Hacker News.
We are not talking about self-applied labels, since parent explicitly says "are referred to as".
So I think it is a very valid point to wonder why some regions came to be referred to (in american english) as latin america, where others that would in principle fit the logical criteria didn't.
I agree it could be put in a more constructive way, but yourself assuming they are not familiar with a particular culture just because you don't like their comment is what actually comes across as rude and dismissive to me.
