Quote Originally Posted by RuriStone View Post
Courtesy wouldn't be asking somebody to leave it would be offering a level of respect to invite the person and confirm they would be ok to join you all so you can play as a group.
It would be discourteous to the 47 other people - who are there to clear - to bring someone into content where the mistake of one person can wipe the entire run.

Quote Originally Posted by RuriStone View Post
Joining in with this content makes us another football player just the same as the other football players. Yes setting up a picnic would be disruptive which I guess is akin to playing badly on purpose but this is not what has happened here.
It does not. The majority of snipers are not at the same prog point as the people doing the runs. If players do not have direct experience with mechanics that have the potential to cause full wipes (Boss 2, Bridges, Boss 4), then they are a genuine danger to the objective of the organised group - to clear.