I think it is because a lot of Americans (and I don't want to generalise because I only hear the people that scream the loudest) are extremely proud of their country even though it isn't that great.

We also don't really understand some of the discussion topics and the decisions that are made. Like gun laws, health care and choice of president (and the way he/she gets chosen)

For me personally it's also the extremists. It is ofc a massive country with a lot of people so the chance of an over the top person being there is bigger. Honestly all the stereotypes exist in the usa, like the very racist redneck, the seks-fearing Christian, the LGBT snowflake, the drug dealing gang menber, extreme feminists and ultimate white guys. It is all there and they are all very stubborn.

That was my rant. I'll state again, I only hear and see things from the outside so ofc I only see the things that stand out.