What kind of content are we talking, here?
1. If it's a new player in dungeons, then I really don't care. This content is almsot throw-away. I occassionally make a challenge of trying to do these things solo. This is true for the MSQ-level Trials too. Not much a new/bad player could do outside of screwing up the pulls. For higher tier activities, like the harder Trials and Raids, it depends on the mission objective. If it's a learning party, I still expect a new player to pick up the ropes quickly as we go. If it's a clear party, absolutely unacceptable.
2. Similar vein to #1. Only, I don't permit UI/keybind to be an excuse for doing poorly in even a learning party.
3. If you were in the mood to play the activity in the first place, you are not having a bad day. This applies to sick people too. If you had the energy and desire to initiate the activity in the first place, then you're not so sick as to excuse interfering with my gameplay experience with bad play.
And this here is the reason people get affronted by bad players, to an almost personal level.
Bad players are not doing things on their own without impacting other players.
You cause a wipe that wasted the last 5 minutes of everyone's lives for an assinine reason, that's 35 collective minutes of other people's lives you have impacted. Because you want to excuse yourself being "bad".
So, should the seven players sacrifice, and happily, their life to make 1 person not have their little feelings hurt for being called a "bad" player?
Or should the bad player be responsible for themselves, and be made to address it?
The needs of the few are not greater than the needs of the many.
This argument looks very similar to why I dislike my taxpayer dollars going towards welfare.