As a DPS main that also plays a Tank, I know where you're coming from. Really, you have to realize that people are extremely inflexible, and your experience is always going to seem worse as a tank because you have two DPS to a party and they are the most numerous role in the game. Problematic DPS are going to range from:

1) People that just start laying into everything without a care in the world. Often, they will pull mobs. Everyone hates them (Archers are extremely guilty of this). They pull, won't let up, and it will always be your fault. Personally, I will let one slide (stuff happens), warn the next time, and just let them die if it reaches a third.

2) If they're outgearing you, sometimes they overestimate how much. I this every now and then. If we're attacking the same mob, I'm so used to not jumping up so high on the aggro table that I will overestimate how much I outgear someone and jump to the aggro table. When this happens I will either use an aggro-dumping move or start wailing on a different mob while you take that one off of me. If its the only mob, you'll probably see me sheath my weapon unless I have Life Surge or something and need to spend it. It won't happen often, and I will usually apologize. Not everyone else will do the same.

3) MMO players are always of the mindset that they have to do the absolute most amount of damage 100% of the time, no matter what happens and every tank, no matter what the situation, must be able to handle this 100% of the time, or they suck. You shouldn't be losing aggro in most content, true, but its going to happen for situations like (1) above and other situations. I find face-roll tanking to be less loosely punished in this game compared to others, and people don't respect that.

In short, as the tank, you are going to notice what EVERYONE is doing, and you're going to be on the spot a lot more than anyone else. You are going to be the most under-appreciated person in the party at all times if anything deviates even slightly from their game plan. The joy of dealing with other people.