Mind you, I wouldn't be surprised if the EU had stuff that was as good if not better than the original stories - I recently played (with some delay, yes, I realize) both of the Knights of the Old Republic computer games, and while those do borrow quite some elements from the movies, even to the extent of almost carbon copying a few lesser characters, I'd argue that both are nevertheless stronger plot-wise and character development-wise than the movies. Definitely compared to the prequel trilogy.

But better stories or not, the movies are obviously the real canon that matters to people, and they were never going to refer too much to comparatively obscure EU canon. Yes, they could have tried to write a story that more or less fits into established EU canon or at least doesn't violate it, but that does limit them creatively, and honestly, why should they? I think Lucas had made it clear enough all along that he did not consider himself bound by EU canon, even if he did exercise at least some minimal control over what they wrote. And let's face it, the fans who are sufficiently into the EU to care about this decision, are per definition also the fans who care so much about Star Wars that, barring really execrable reviews, they are almost guaranteed to go see the new movies.

And I do not think that such a decision throws the EU onto "the thrash heap". Okay, future generations of readers will now become less likely to read the existing EU novels, granted, but then that probably would have been the case anyway - not too many of them are sufficiently big classics that they could've avoided that fate. Those who are already fans are free to continue to consider their favourite EU plotlines as canon - they were already used to most people not being aware of this canon, the only difference is that now most people will be aware of a different canon, instead. Not really that different from what happens when books are turned into movies/TV series and the movie/series deviates on important points from the book (Song of Ice and Fire is the obvious example of the moment) - separate groups of people consider different things to be "canon".

And really, isn't it more exciting to have new stories in which radical unexpected changes to the Star Wars universe can still occur, than just a rehashing of various EU novels, or a filling in of the blanks between them?