I think the fanbases you are talking about is the other way around. Out of all of my friends who love SW, only 1 really has read the EU novels, as he has kinda filled me in through the years of the characters like Mara Jade, Han/Leia's twins, etc.
I know several fans who have floor-to-ceiling bookcases full of Star Wars books... There is a huge amount of books that share a continuity, starting with the Thrawn trilogy in 1992 (which introduced Mara Jade and set the EU going) up until only a year or two ago, right before Lucasfilms "Legends" announcement. That's twenty years of books! And it is not only books, but also video games, comic books and collectible figures within the same major continuity.
When I say "fan", I am talking about people who are real fans, not just people who like Star Wars. Practically everyone likes Star Wars, but not everyone is a fan. The fan community is so much larger than the OT-diehards on this forum who see Star Wars as being only the three original movies.
Every person that I know personally who I would classify as being a Star Wars fan has read at least one book in the post-ROTJ EU continuity. People know and like these characters. For example, in my local 501st Garrison alone, there is soon to be a third Mara Jade costumer.
Star Wars fans tend to buy not only books but a whole lot of other merchandise, and that has provided for a a significant portion of Lucasfilm's revenue in-between the movies.
That is why I say that I think that Lucasfilm would be disrespectful to the fans if they just ditched the post-ROTJ EU continuity outright.
Making a movie that is based on stories millions and millions and millions of people have never read could be seen as a 'giant middle-finger' to the lovers of Star Wars moives.
Making a good movie for those who have not read any books and respecting the broad strokes of the post-ROTJ EU are not mutually exclusive.