Nothing you quoted had anything to do with relative importance of the roles, so I'm not even sure where you got it from. I can only guess that you conflated "responsibility" with "importance" which is a pretty naive viewpoint. DPS is *important* because of various enrage mechanisms, but it doesn't have a high degree of responsibility because, when they screw up, things don't fall apart and, most of the time, no one notices. A bad tank or a bad healer is going to be obvious from the start. As such, it's got more responsibility because there are more people that explicitly rely upon them.
You're simply proving my point. A bad DPS passes under the radar because it's hard to notice a bad DPS, especially since parsers aren't really used often. A bad tank is going to get hassled constantly because the other members of the team count on the tank actually doing their job well so that the they can do their job well. DPS and healers can't do their jobs very well when they're getting punched in the face; healers have a harder time doing their jobs when bad tanks stand in bad shit.As for why people dislike playing tanks, I think it's more than just "Tanks have so much responsibility ermagah!!!" I leveled my PLD to 50 and got a relic weapon, doing duty roulette every day to get more practice, and got 1000% more flack than I ever got as a DPS on my worst days. Like hell I would want to continue tanking after that. Only good thing is that people will mindlessly give you commendations.
It's probably a safe bet that you were hassled as much as you were because you were simply a bad tank. A bad tank is going to get a helluva lot worse punishment than a bad DPS, which groks with your own experiences. The fact that you somehow missed that connection doesn't really bode well for your ability to actually contribute to the discussion since you're the archetype of those players that don't play tanks for the exact reasons I outlined.