You would concede though, that you are far more concerned with plot logistics, internal logic and realism than the vast, vast majority of people who would ever want to see a fourth
Mission:Impossible film, would you not? I'll grant you that it's pretty unlikely that Russia would buy into the idea of an American attack so decidedly in the current climate, but I also think it's even less likely that there are a group of four special agents so skilled (and lucky!) that they could single handedly save parts or all of the world by climbing up a building with magnetic gloves, and that is the premise I'm buying into when I buy a ticket to see the film.
This is not to say I don't agree with some of your criticisms; certainly, the villain is a complete non-entity.
The junk science in DUD failed on screen because the filmmakers kept a straight face for the entire production. Ghost Protocol revels in the absurd and accepts the fact that what it's throwing at you is ridiculous. The entire story is told with tongue firmly in cheek, and that's why it works.
Hmm, I think it's a tad disingenuous to claim DAD takes itself more seriously than
Ghost Protocol. Despite DAD's fairly serious opening, I'd say it was quite the opposite.