I don't see relatively new players as bad players. They haven't learned yet, and eventually they will. It takes time to find your way to play and some have to experiment with other classes to find the right one for them to play. An occasional mistake doesn't make them bad, as I've seen people claiming to be pro, have better gear than me, and be the single cause to every wipe I'd experience in the dungeon run. Had this happen with Amdapor Keep, when the WHT kept dropping the purple pulsing balls of death right in the fighting area of the boss. He was in i70 gear. He took his time, but learned how to play the boss, after around 9 wipes. We beat the dungeon after 2 tanks left.

I certainly don't think he was bad because of his performance since he had better gear than I did.

What I consider Bad Players are the people who get slighted by the appearance of a new player, start harassing the player and or team they are on for a few mistakes. A CT run I had one guy from another team just bashing everyone else. He'd throw insults around at other teams for a accident or if we wiped because his team rushed in without us. At one point, one of our tanks trolled him and his team, we were forced to kick him after that cause he was just becoming a liability. The same guy insulting others just kept with increasing negative remarks towards the dungeon run when he and his team started to fall behind. He alone made the entire CT experience a horrible run. We didn't even get through Behemoth's part because he and his friends kept bailing and refused to help the other teams. He is what I'd call a bad player. Someone who maliciously causes trouble for others.

New Players can learn and get better, but you can't fix or change people who live to cause trouble for others.