Yeah i think you are right here. No one should even be using the tanks to get to their shields. It's not very hard to walk off the tank and get to your shield within the (10?) seconds defensive systems is being cast.
one can argue that you loose time to dps from running. Let say you loose 8 secs per shield phase, 4 shield phases, so a total of 32 seconds total in the fight... depending on how much dps people are pushing out walking of flying can mean the difference between death to an enrage or a kill. With that said though people shouldnt be killing themselves to dps; meaning if for what ever reason you're sitting at 50% life and DD on you, you should be poping a CD and running.