You know, I been telling a story lately, though people may be tired of hearing it. It is a few days old and posted about it in the vent thing. I am just shocked someone did try get away with it. So the thing was, someone that I talk to was doing that final expert dungeon, the one you need ilevel 300 for. It was noticed right away on first pull it was going slow. (I had to explain in yet another thread with a similar issue that experienced players can notice slow or fast pacing on the first pull, you do not need a parser.) So she checked the gear while taking note thunder was not being used at all. So she commented about asking if they had i290 weapon from job quest and to use thunder, no comment was given. By the time they where on the last pull before the first boss, she said stop and to give them a minute. After waiting for a long time for a reply the DPS in question made a comment questioning why they are asking about gear. So finally having enough between the poor performance and poor communication said "Please do not do high level content without doing your lv 70 job quest" then kicked them.
So that story alone proves what you are saying to be false. But I am not sure what the norm is. In this other vent thread one poster was talking about how running into bad dps is rare and admitted he can't notice if people are doing their jobs or not. If that is common ten I guess on average they do get away with it more often then not, and that would support the idea how that BLM made it to the final expert dungeon being not prepared gear wise, rotation wise and spell wise.
Going to the final expert dungeon having fire III to fire I, sometimes casting fire II for a rotation and never thunder,flare, or foul(since they did not have it) has no excuse. This game badly needs tutorial requirements before being able to queue up for some content. "requirements not met, level 70 job quest" " requirements not met, level 300 weapon or above" "requirements not met, clearing hall of novice advanced rotations" If the player base are going to act like babies, they should be treated like it, it is no different then removing chat from feast.