tanking

[TouchandFeel]

snip

If by "pulls back to back" you mean pulling one group of mobs at a time, killing them and then immediately moving on to the next and then the next and so on, then quite frankly I could see why someone may get impatient as it is actually quite inefficient and slows things down terribly.
It is much better to just do larger pulls than consecutive smaller pulls if your party can handle it. Large pulls maximize the potential damage output of AoE attacks and quite frankly as long as most players are playing halfway decently and aren't terribly under-geared, big pulls should be a breeze.
Doing consecutive small pulls just spreads the effort and completion time out unnecessarily.

While adjusting to your party and slowing down if necessary is something a good tank should do, pushing the party to live up to their potential and actually perform to the level they could and really should is also something any good tank or really any good player should do, as long as done in a supportive way.