I was catching up on my RSS feeds and I found [this review of the last Hobbit movie by Ars Technica]. Sums up my feelings perfectly:
There's one big thing that doomed these movies from the outset—the fiscally smart but artistically bankrupt decision to make a single, shortish children's novel into three feature-length prequel films.
Artistically bankrupt. Perfect way to put it.
What these movies desperately need are boundaries, reasons to condense scenes or cut them out entirely instead of reasons to pile on more. Chopping these down into a pair of two-and-a-half hour movies would drastically improve the pacing even if you didn't address the characterization or the tone issues. You could leave around three hours of slow-motion action sequences, goblin chases, and Radagast the Brown on the cutting room floor! Sounds great, doesn't it?
Couldn't have said it better myself.