Okay let me offer the reasons why WoD ending was the best thing about the expansion.
WoD was a horrible expansion that offered me no fun whatsoever. I saw the lore at Blizzcon, said nope, and came back later thinking that I would have some shit to catch up on. I was wrong. There was literally nothing to do at all. It took me 4 weeks to get my legendary ring in LFR. I heard stories of people standing in their garrisons all day and... well guess what I did? Stand in my garrison all day. The raiding guild I was in during MoP achieved somewhere around top 40 or 30 om the world for mythic Highmaul and then burnt out cuz the expansion was so terrible it offered them nothing else to do. WoD was the first time I had unsubbed for most of an expansion since... never. Literally never. I've been playing since Vanilla WoW with an active sub for all those years and WoD was so bad I couldn't play it.
I was excited when I got to see all the cool shit in Legion. Best part of WoD was the ending.