To drive a huge hole through your argument it's not necessarily the same people leaving every game either which lends credence to my point that circumstances in peoples' lives differ from week to week and some of the time they have other places they need / want to be.
More broadly though I think you, wilfully or otherwise, misjudge the motivation of these people. They aren't seeking to improve the atmosphere like many of the guys who post sensibly on the atmosphere thread. They are seeking to self praise by criticising other blues presumably because like all bullies it makes them feel temporarily better at the hand life's dealt them. As i keep saying, it's needy, delusional and pitiful to an extent. I feel a certain amount of sympathy for some of them.
I don't see a 444 page thread about fans who miss parts of the game to buy food or alcohol.
No 444 page thread dedicated to non singers.