Please elaborate...what does 'Learn to play' entitle? I really hate the people that say learn to play then come back, without helping the 'n00b' by teaching him some strategies you picked up along the way. It just comes off as elitest, which is what the OP is adressing in his post. Be helpful and give the newbies some tips and tricks to help improve their game, rather then scold them for sucking and telling them to 'Learn to play, then come back.'\
Check the strategies forum?
There ya go! Perfect. Tell the newbies your playing with to check the strategy forums after the game and they will learn a lot! I did the first day I got the game (after receaving a beatdown by normal AI in SP lol!). So guys, saying "N00b you are terrible, go learn to play and come back" will turn many people off from the community and game. Instead, when your n00b teammate is feeding the other team, hold back your anger and tell them "Hey man, after this game check out the DG website and read the strat forums. Lots of good stuff you can learn from there."
Granted a lot of casual players wont care and wont listen, but thats life and we have to deal with it. But at least approach it civil and try to help.