Is it so hard to understand, that anyone who joins a random group of players (no matter by PF or DF), should at least put some minor effort into it? I m not speaking of 200%-Ultra-Hardcore-Raid-Skills in a dungeon. I m speaking of basics like doing mechanics and not being afk 50% of your time.

But its just a game!
- Yes it is. But its a game you play with other people. If you dont want to play WITH other people, there are tons of singleplayer games waiting for you. But FFXIV is an MMORPG.

But I want to play like I want!
- Then go with your friends or find some FC-members with the same attitude. Its pretty impolite to force your playstyle to 3-7 other people. Show some respect and do your job!

I m a healer, so my job is to heal
- Fine. I m a tank, my job is to tank. I m tanking every AoE now and tons of monsters. You want to heal? I give you something to heal!