I really liked the new effects when I first saw them and wondered why was there complaining, but having read this thread, I fully empathize with the complainers having seen examples and read explanations of it. It's clearly not nostalgia or stubbornness exclusively, they may factor in but not as a main reason, and I would say they are negligible.
I believe my personal opinion hasn't changed, and I still enjoy them, but they are clearly not as good as they should have been.
Finally, when Star Trek was made, those people were doing their best they could to do accomplish what they set out to do, they were trying to create a masterpiece.
When the TOS-R project was done, they were doing it quick and cheap and trying to squeeze money out of something over 30 years old, even if at least some of the participants cared they still weren't invested, IMO, and it shows.