Etiquette sends a strong signal that you're socially reliable. Working in groups is difficult and you can't just brute force it by waving your hands and saying

Etiquette sends a strong signal that you're socially reliable. Working in groups is difficult and you can't just brute force it by waving your hands and saying you only care about the work or about being nice or whatever. Disagreements happen constantly and you can't just fight or disband the group every time you don't reach consensus, or you can but your group will be quickly outcompeted by a more functional group. Etiquette and other social skills allow for continued cooperation in social circumstances with many moving parts and competing interests. Doing things like sitting down when others sit down, etc. are really just table stakes. If you don't have the basics of reading a situation and applying rudimentary social norms appropriately you're kind of socially radioactive and will be treated accordingly, i.e. you won't move on to the more interesting interactions and you'll be placed in a baby zone unless people need to negotiate with you for specific resources. Programmers can get away with this better than most because it's a skill people need, but it's still kind of a disaster not to get decent with this stuff and you probably won't even understand how much it's damaging you.