He is controversial: I've seen people describe him as "Good lore builder, pretty bad at actually writing."

He created the Maw and Kessel, purple and double-bladed lightsabers, Exar Kun, etc. that people liked, but you had to slog through long flowery dialogue to get through it. Meh, I am mostly okay with that personally, but yeah some people can't stand it.

Edit: I want to add that the vast majority of YouTube videos are so much worse in terms of blah blah blahbity blah I-want-to-make-this-video-just-over-10-minutes-long-so-I-can-sell-moar-ads. Books at least I can just go at my own pace and slow down or even skim a bit and speed up if I wish, while such videos (which are pretty much all of them?) are basically take-it-or-leave-it, so yeah I'm much more forgiving of such things when they appear in book form:-).