I've read through this and thought about it, and I think that for me, it really has to be the blatant disdain for the original trilogy--which covers everything from Qui-Gonn and not Obi-Wan finding Anakin to the replacement of Shaw with Hayden in the RotJ DVD.

Not to say that the other stuff mentioned--midichlorians, awful plot, awful dialogue, awful performances (with the obvious exceptions of Palpatine and Obi-Wan)--isn't awful, but a lot of it (especially the midichlorians) is part and parcel of the disdain for the OT.