The review in this afternoon's paper began thus:

With the phenomenal success of The Lord Of the Rings, Harry Potter and The Chronicles of Narnia, it should come as no shock that Tinseltown producers are scurrying like mad to acquire the rights to all kinds of obscure works of fantasy literature. ...

The three listed have each independantly acquired a huge following and a decent reputation. And, except for Mr Potter, had been around quite a long time, as well (J. K. Rowling's creation had other redeeming qualities). In the field of fantasy, there are many many many other works with longer pedigrees than Eragon. I found just today that a TV series based on Anne McAffrey's Dragonriders of Pern was cast and piloted a few years ago, but Warner asked for so many changes that the producer cancelled the whole thing. And probably quite rightly, too. By contrast, the writer of Eragon may have simply not had the ability (experience, wherewithal, clout...) to stand up to the required 'improvements' from the studio and thus your disappointments.

Wade.

Well I guess everyone has to start somewhere.

But day-amn did he get some bad advice.

Studio: We want to change this, this, this, this, this, this and this, and lose these fifteen scenes...
Author: um...
Fanbase (just out of hearing): No! Don't do it!
Author: well... perhaps...
Fanbase (even further out of hearing): No!! NO!!! They'll murder it!!!!
Authot: .... well, okay. ... I guess.
Studio: Great!

Wade.