The fact of the matter is that the books will always be there. NO ONE is saying, "Oh hey, let's throw the books into big piles and burn them!"
It's the same thing with comics and their TV shows and movies. Are the latter canon? No. Have they ever been? No. But has that ever stopped people from loving them all the same? Once again, no. Same goes for the books. So what if they aren't canon? So what if they aren't going to be featured in a movie?
They will still be there. You can still return to them. You can still enjoy them.
So there really is no reason to complain. None at all in fact.
Actually, I can understand why one could complain. An example being the on-going Star Wars: Legacy series. With them discarding the EU Post-ROTJ, the series that are still on-going will either have to be 1) Retconned, 2) Altered, or 3) Discarded in it's entirety. Case in point, Ania Solo which Legacy #2 seems to follow.
Now it could be said, that only two parts of that particular series has been put out and who knows the numbers of people who've read it, which would be a fair statement. But for those who HAVE read it or the author who is currently working on it, that takes the story and puts it into a Null zone for them.
Legacy #1 following the One Sith, Darth Krayt, Cade Skywalker, and everyone surrounding them also now gets affected. While they are a lot into the future, what happens to their storylines, and the actions of those surrounding them?
The action of the SW-Disney Merger and the decision to "streamline" the EU for purposes of making a cohesive story in lieu of the new movies is mostly for them to allow access around the immediate timeline Post-ROTJ and the children of those characters. But for more farther reaching in the timeline, this can have repercussions and effects. I understand that the books are still there, but while you can still read them, being told that those stories have no real place in the future Canon is still a disdainful thing to be told.
Anywho, that's just my two credits in the situation.
