That's exactly why. Hollywood (insert any greedy movie mass production plant here) rapes the source material and makes it different at best, or an unrecognizable mess at worst.
The Hobbit is a book for kids about a little guy with hairy feet going on an adventure. Gotta make an EPIC SAGA and stretch it for three movies too.
Bottom line: okay movies seem terrible after reading great books they're based upon.
It's all about profit. No Hollywood adaptation is complete without the annoying love story, and overexaggerating certain things, leaving lots of
detail out, or totally changing it.
This applies regardless of the source material. If it sells better, they'll do it.