There were plenty of great stories they could have preserved while leaving room for new canon stories to be told.
And they’re all available in paper back with a little yellow “legends” banner. What difference does it make if they’re official?
It would at least make the creators of the products efforts not seem in vain. For a while these people were under the impression that their works were official so to have Disney say “Yeah…you know all the hours you spent on and all the love you put into creating original stories that expanded the lore of Star Wars…we’re going to scrap all that so we can make more money”. Secondly, headcanon is good and all but every time I partake in EU material I find myself comparing it to what’s canon and I can’t stop my brain from conjuring up those thoughts.