I have an opinion on this!
EVERYONE: Aw...
No, no, hear me out.
I don't think it was intentional to write off the Extended Universe without a second thought. I think actual thought was put into it. The character of Mara Jade only works if episode VII, VIII, and IX had come out in the eighties or nineties. Not only that, but we, as an audience, would not be able to be surprised if they used any of the Post-ROTJ stories, or even did a kind of adaptation of a mixed story of some kind. So, that ruled out adaptation. Time and Surprise was lost.
They /could/ have told a new story while keeping the Extended Universe canon but that would mean having to delve into over 30 years of resources without losing continuity.
It was just easier, and cheaper, to start from scratch.
Having said all that, yes. I agree.
The Extended Universe is far superior then the Post-Disney EU.