"Do not talk to me of Peter Jackson! His pride has muddled his wits, and spoilt his films!"- Saruman the Wise
We can rant for ages about the Hobbit. But here is a few points.
Disregard of the books. Yes the Lord of the Rings films have a lot of changes, but the books were always respected as the ultimate life of the stories. PJ did take them and make them his own, (which was sometimes for the worse) but overall the books were treated as the higher authority. With the Hobbit films though, PJ openly mocks the books (and Tolkien) and makes believe that his own additions and changes are what really makes these films special. This was greatly the case with the last two Hobbit films...
Breaking the spell. All stories are set in a world, even a fantasy one. There are certain things which can happen and other things which cannot. This is the reality that the author or director weaves into the story to give it plausibility and life. So often in the Hobbit films you are shocked by things that break the story's spell or enchantment. We aren't just talking about things that are "un-Middle-earth." Many elements of the Hobbit films do not belong in the story or setting, or even the genre of film.
If its cheaper or easier to do it CGI, why not? PJ overuses CGI. George Lucas CGI bug. In the Lord of the Rings, CGI was only used when the real thing wouldn't work. Monsters have to be done by CGI. But then we don't see monsters every day. When you have ordinary things CGI though, the audience sees it immediately. Overuse of CGI is also due to last minute changes and indecision on PJ's part.
Do you want this or not? PJ doesn't seem to have been able to make up his mind on what he wanted these movies to be like. WETA came up with some amazing ideas for these films, and many scenes were made with their designs. PJ seems to have changed his mind somewhere near the end however. Great designs and ideas were thrown out and exchanged for flat and run of the mill work. The standard of these films has dropped, especially in the last two. This is proved by lack of Oscar Awards, which crowned the Lord of the Rings films. These changes might have been influenced by the market these movies were aimed at.
Commercialisation. These films were made for wider audiences in mind. Youngsters and popcorn munchers especially, who just want entertainment and don't think to much behind the story. Characters and plot depth are nothing beside ridiculous action and jaw dropping CGI stunts. When the Return of the King finished, people just sat in their seats in the cinema and where dumbfounded. With the Battle of the Five Armies, people just got up or sat on texting on their phones.
There is much to like in the Hobbit movies, but also much to complain about. Some parts are really memorable and we love them. The Lord of the Rings films are far superior to the Hobbit though. They are not perfect, and there is a lot we don't like in them, but overall they are great films.
That's just our opinion. The great thing is that everyone is different and has different opinions.
Elladan & Elrohir