I'm wondering if it could be that you're comparing dungeon-experience with raid/ex-primal experience here?
It sounded a bit like you were talking about tanks that arent performing great in dungeons - and compared that to dps-experience. Personally, I've never seen DPS in a normal dungeon being kicked because they dealt below 5k damage, that sounds more like a Savage/Ex-Primal scenario. And even then it makes little sense, to be honest.
I assume you know the answer to your question though - which job is the highste in demand? Tanks. Followed by healers. DPS is easly replaced.
And in case I'm right and you are comparing dungeons to raids: I think for a dungeon it doesnt matter to much to most people. Its annoying at best, but hey, just continue watching netflix and be happy that there is a tank in teh first place and you can progress. You'll be out of there in 20 minutes either way.
For a raid you either want to make serious progress or farm - both commitments over a longer period of time, so you can be picky.
Also keep in mind that other things can come in play when it comes to kicking people - like ignoring mechanics, for example.
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To share two stories of truely horrible DPS not being kicked: My friends and I were farming Skalla over the weekend to get some tank coats for the fashion report. Warrior, Whitemage and me on bard.
For one of the runs we got a second bard. Who didnt use their songs half of the time - at least I didnt get the crit-buff, while they got mine. It was slightly infuriating... specially when they spoke up at the last boss and telling our Warrior to turn it to the side to make it easier to avoid the tail - and yes, thats a good idea, I do that too. But honestly: Its a round arena, so not really needed... you can just move to a safe spot. Specially as bard you lose nothing from having to move. You do lose something from not using your freaking songs though! Damn, 2% Crit buff isnt much (even though we were losing out on their Battle Voice aswell) but as someone who really likes bard, this was frustrating.
Second story is actually worse - we got a BLM, horray, more AoE!
Turned out though: This BLM didnt know how to BLM. They did have decent gear, BLM being their only level 70, looked like it was the main... and yet... Enochian was dropped all the time, casts altered between Blizarrd III and Thunder III, Fire IV was nowhere to be seen and we dont even need to think about Triple-Flare. Their DPS was something around 900 to 1k.
Communication? Zero.
Respond to suggestions? Nada.
If there hadnt been loot up we would have kicked them before the last boss - no effort to learn, to say something, to improve... and no sign of having understood the basics of your rotation at level 70...