I said i could shoot it down as great, not drop it down to crap
But here we go anyway:
The besiegning of Suramar had no characters standing out, a bad ending with us killing no character of importance and changed nothing.
Durotans brother, Ga'nar, my favorite character in WoD, was killed off in comic factor by killing 2 dudes, that anybody could have killed and ended up mattering little in the overall story.
The broken shore defeat failed big, because Tyrion died nearly off screen, Varian and Voljin died after we not having any interaction with them for an entire expansion(several years) and we learnt nothing from it.
While i understand Suramar and Ga'nar, i don't understand why you see the Broken shore as a great lore moment. We came too late to actually see the Argent Crusade be destroyed, which could have been a great moment to show us, that we could actually lose. Varians death was needed, but having it come after an entire expansion where we had no interaction with him, nearly forgetting that he is there, greatly the emotional effect on the player and makes his death pretty wasted. Vol'jin did not even have enough time as Warchief to create a relationship with the player, so his death was also pretty shallow after his long absence.
I don't think these moments are completly crap, but they are not good. Ga'nar was an extremly great character, but Blizzard completly wasted him. He should have died in glorious battle, not being buried in stone, that he could have jumped away from >< Suramar is also pretty alright, but none of the characters in the story interact with each other, even when there is given such great opportunity for elves to actually talk about elves. The suramar story also lead to nothing. The city was not retaken, we killed no enemy worth while, hell when we faced the big end boss, Elisandes new first arcanist, we meet her like the 2nd time when we kill her. Not alot time to create an image of big enemy.
So there you go. There are flaws everwhere, big and small. Suramar and Ga'nar, and i will even give you the prince Farondis story, is not trash, but far from being anything that can be called great lore.