I wonder if this is because Dreamworks Theater got a better response for NOT being 3D.  (Note:  this is all purely speculation on my part, I have no concrete evidence whatsoever that DWT got a better response from the public... but it sure does for me and I imagine the ride ops, lol)
I know I visit DWT way, way more than I ever did Shrek (the smoother motion of the seats helps, too--but it's mainly because of it not being 3D).  I sort of wonder if I'll end up enjoying Minions a bit more--admittedly I don't ride that too often either.  Curious to give it a try!