This all depends on the person. MANY people go into a league or a turnament thinking they are better than they really are (since they can beat their other drunk friends usually) or go into it thinking they are going to be hanging out and drinking with a side of pool.
If they are weak willed or have fragile egos, they will quit in a week. The ones that actually want to play will see how your game is so different than theirs and would want to start working to get to your level.
Don't know how many times I've seen a guy come in and be all gung-ho about playing, gets his butt handed to him by a B player and we never see him again. My son beat a new player by breaking and running the last rack on him to win 3-0, by the look of the guys face and how he was acting I though my son did something wrong like make fun of him or not shake hands. Turned out my son shook hands and all, but the guy was just stunned that this 15 yr old ran out the rack on him and he just sat there. Have not seen him again for the tournament since.
On the other hand, there was a youngish kid that I played that was new to our weekly tournament, I ran out the first rack I played with him, he said "wow, I've never played anyone like this before", BUT he came back over and over, and got good enough to get in the finals one week. I love teaching and explaining shots to people like that, and it helps grow the room and tournament when those players stick around.