I suppose that it ties in with the fact that I don't believe the way Anakin is shown to turn to the Dark Side. It just doesn't hold water for me. But it also doesn't sit well with OT Vader, either. The sudden outburst jars with his whole attitude on Mustafar and then when we catch up with him in the OT. It's just not Vader. Couple that with the fact that the whole scene seems to have been edited together from Young Frankenstein and I'm afraid it just leaves me cold.