In the real world, a book can be entertaining or enjoyable and still be bad. The notion that a book has to be good because people enjoy it is almost as silly as a book being good because it sells well.

Now, I am a fan of Bob's. The Drizzt books introduced me to fantasy and really got me back into reading. Hell, I'm even a moderator on his official forums. But there is no denying that his books are poorly written. They are enjoyable. They are entertaining. They aren't very good. Seems like most of the people who argue that they are tend to be the ones who haven't really read anything other than tie-ins.