I'm going to say this. About 95% of the players in the roulette know how to play their class and role. Funny thing is, even half the 'newbies' you see.. you know the ones that give you bonus tomestones are veterans on alts. The players that do not know what they are doing form a very small percentage. Out of that percentage most of them do not join groups because of that limitation.

So what's the real problem? Laziness.

Why does a DPS need to do a full rotation when the tank, other DPS, and likely healer will easily make up for it?
Why does a tank need to do a full rotation to put out any DPS when there are two others that will carry it. Or move out of AOE when a healer will keep them alive?
Why does a healer need to pay much attention when likely the others will be geared enough to snooze through it?

I've done quite a few roulette in the last month. Gearing up a few classes and see the issue from multiple angles. I've yet to see a player who doesn't know what they are doing in the Duty Finder outside the Leveling Roulette (and even then its only because someone might be learning pulls, playing a class in Sastasha is literally 1-2). Occasionally I get someone who hasn't done a fight before. But they know their class well enough.

From time to time I get a player who exibits issues like you all bring up in repost after repost. But usually a quick chiding gets them to play properly. Those that don't get booted. Seriously people, just use the vote kick. The devs gave you a tool, use it. Stop being a lazy player yourself. You're no different than the players you complain about.

Maybe players like the OP should be forced into a Solo Duty where they have to pick the NPC that is slacking off to be vote kicked. Because apparently that's function that eludes everyone these days.