The worst thing about shitters isn't that they don't do any damage, it's that they block better players from retreating or taking key positions. This is probably the main reason how someone can get below 45% long term WR (which indicates that you're actually worse than useless, i.e. the team would be better off with just 14 tanks instead).
Playing tier X some more, and apart from the more shit meta, my biggest issue remains penetrating shots that I easily penetrate when driving a tier VIII tank in a tier X battle.