Here's one that happened just a moment ago:
Paladin can't keep hate on trash or the boss. Both DPS are constantly pulling aggro as well as the healer. After the first boss is when we finally say something after nearly wiping, mainly due to all four of us taking damage nearly the entire time.

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This is one of the reasons why you can't mentor in FFXIV - not the way it
should be, anyway. It's not like you can report the guy, even though he's purposely potentially screwing you over if other tanks decide to leave immediately (which did happen until we finally got one that stayed). All this person cared about is, I guess, the feeling of being bullied because other players were too nice to stop and telling them they aren't performing their job previously, potentially running into the same situation we did. An overly sensitive player being told they aren't doing what they need to be doing, being called out on it and then dealing with a tantrum.
And yes, the tank said that and left
immediately; so fast that they were gone before the "just helping" got sent.