Of course, there are those players who don't care but I think it all depends on the person playing the tank. I mean if the player is new to MMO and choose to tank first, there is some chance that he doesn't understand the mechanics as well as another experienced player in MMO, even if that one did not ever tanked before. Especially if anybody did'nt tell him anything. I am leveling currently a WAR and the enimity mechanic is not clear at all from the quests: you are fighting alone or with an NPC that doesn't die (I am sure that the NPC can perform the quest alone XD). I understand what the quests are for but it is also because I already knew it. Also if this new tank is struggling to hold aggro, because he doesn't understand mechanics, I am not sure he is able to watch to other people in the party. In Aurum Vale, I had this tank who was facing the last boss towards the party (I don't remeber well but I think the healer was new also as he didn't move). We wiped. Then I just told him that it is a good habit to face the mobs away from the party, especially the healer. He did and we were doing fine. I think that he was a new player and nobody never told him anthing.

Also, most guides are focusing on stats, rotations and so forth. But it is hard (well I never saw one) to find one that talks about basic features such as positioning mobs, waiting to dps or whatever. They all assume that the player already knows the basics which is not really true. When you were learning maths, for instance, did you learn first to do addition or directly vector spaces?