Trashtalking and teabagging is part of the fun.
Maybe for some, but I always found that part of multiplayer to be a turn off. I usually jump servers once a match is over if the chat is just trashtalking.
Personally for me I am more interested in MP vs SP. Single Player never feels the same as multiplayer. I am not even talking about from a difficulty perspective, but more from how the game feels. The guns don't feel the same, the shooting doesn't feel the same, the damage is usually lowered, etc. I think the last single player I enjoyed was from Soldier of Fortune 2 and that was due to the damage model. Also the game to me felt the same way both in Single Player and Multiplayer.