I like to approach canon as a puzzle to piece together but one that's non-binding. I enjoy playing with it, thinking about and - especially - thinking about how I'd fix. (You wouldn't believe the reworked, painstakingly intricate revisions to the Prequel Trilogy I've made in my head. Unfilmable, probably unwatchable!) I like to match stuff up and come up with outs and explanations. Star Wars has always been more slapdash in how it bridges canons and the "layers" to explain away glitches. Trek has been much more utilitarian, "Canonical onto themselves at times but the shows/movies rule out, no if/ands/buts." Doctor Who has the lovely idea that it's all canon and also all non-canon by the very conceit of the show. There are three Atlantises on screen! And I find that much more refreshing, it all works until it doesn't but it doesn't matter.
In particular, I feel that Star Wars and Lucas himself set fans approach to and thoughts about canon apart. Fans knew that George liked some of the things that were produced. He wasn't like other IP owners who could care less about the tie-ins. He bought copies of Dark Empire for his staff because he liked it. He named Imperial Homeward Coruscant because it had become the default name among the tie-ins and fans. Those tips of the hat (not completely missing from other franchises) were given undue weight and so it goes.
As to the "Legends" banner on the old-canon Star Wars novels, well... That's DelRey/Disney having their cake and eating it too. From what I understand from folks who work in publishing and book sales, a lot of the Star Wars books are evergreen. Heir to the Empire still moves copies, enough to justify the 20th Anniversary edition a few years back.