Team chat and all chat are backward. Industry standard is team chat on enter and all chat on shift+enter. It's that way so people can communicate with their team quickly, but have to actively try to communicate with the enemy. The amount of accidental all chatting that goes on with the current system is unsustainable.
Default behavior should not be counter intuitive and disadvantageous. The existence of an option to change it manually does not change the fact that the argument is about the default behavior that new players (And most who never look at the options menu) encounter.
