It's an argument between three things, safety, speed, and stress. People don't necessarily like the stress of not knowing what mob you are attacking next. Also, people definitely don't like the stress of, "This tank isn't marking. Does he know what he's doing?" Having a pull-more-than-one-group-AOE-party will definitely tilt the encounter more towards speed/stress and it will be over faster assuming everything goes to plan. You have be far more alert. A strict pull-one-group-kill-one-mob-at-a-time strategy is very low stress and high safety. A focused mob dies relatively quickly vs an AOE'd mob. Every mob that dies is less damage for the healer to heal. Sometimes people just want to autopilot a dungeon. They may have come off of a hard fight on an alt class and just don't want to remain too alert. Or maybe they just want a relaxing run vs a fast run. As a tank, you dictate the pace. However, it is not a dictatorship. Try to find the pace everyone is happy with, and people will be happy with you.

P.S. I have found that you can tell when an encounter is being tanked well based on one factor, Chaos. Generally speaking, the more chaos that is going on, the less skilled/more inexperienced your tank is. A tank that has mastered a dungeon makes it seem very mundane by explaining nuances and conducting encounters in an orderly manner. Pharos Sirius is not the nightmare so many people make it out to be. Keep the chaos low and people will love it.