Low geared alts of high IO players are the quickest to leave when things don’t go smoothly.
Those who complain about others dps in the chat more than actually doing the dungeon.
These are the groups that I am happy to leave, personally.
When some idiot thinks they are going to save the run with their “constructive criticism” (IE “mage suxlol”) I call it good and nope out.
I do not care if this means I’m a leaver. I am not obligated to sit there suffering abuse or the abuse of others and I am not obligated to ensure the success of people that partake in that abuse.