Everytime I here individualism brought up by someone from Hexbear or Lemmygrad, it gets talked about as if it's categorically bad and wrong. Why is that?
This goes against everything I've learned in the states, where we consider individualism a necessary part of being a responsible and moral person, whereas collectivism strips us of our humanity and turns us into subhuman insectoid creatures incapable of thought.
Because we aren't living in some videogame world, we're all here together and our actions affect one another. If we want to build a functional, fair and equitable society for all, we need to work together towards a common goal in an organized way. The capitalist mythology where everyone can get rich and live a luxurious life if they grind hard enough is mathematically impossible, the very word 'rich' implies the inequality of society, being rich is being rich at the expense of everyone else. Capitalist individualism also changes the way people think about society and the world, real solidarity between the members of society cannot exist in a society which needs greed and selfishness to survive. The kind of person capitalism breeds by its very nature is the "your pain is my survival" kind.
All that said, communists are not against personal traits and people having a different character. That is not the individualism we're against. The individualism we're against is the illusion that everyone must fight for themselves individually and somehow still have a society that is not brutal and cannibalistic. People by their very nature are different in their own special ways, have their own interests and lives, have things they're good and bad at. If anything, socialism increases a person's ability to reach for their personal interests because it breaks the class barriers for them. For example, in capitalism a bourgeois person has the money and time needed to do anything they like in their spare time, but a worker who is paid just enough to survive, who has barely enough time to do their own house work, who is drained of energy by the time they get home, obviously do not have that same ease as with the bourgeois person. In socialism all workers can get from society just as much as they give to it, the surplus value which capitalism exploits no longer exists. That's how Soviet people massively improved their cultural level in a very short time span after the revolution, the arts and science etc. that Soviet society produced can still be noticed today.