The really big problem with the story is simply that it grinds your sense of progression to a screeching halt, and simultaneously gates content so any time you spend on other activities only prolongs how long your progression is capped.

You can't really progress your main class because you have no access to higher level content until you've cleared each expansion and post quests.
You can't progress any alternate classes, because the glut of the quests you're stuck on are max level for where the game has capped your progress.


The MSQ just doesn't meaningfully interact with the reward systems of the game, instead it locks you out of the reward system of the game. It just says "No XP or loot for you until you've done all of this". Sure, you eventually hit the point where you're level 90 on every class you want to play and you have item level 600 gear. Maybe then XP and loot don't really matter anymore and you'll be glad for story quests that keep you entertained. But trapping you in a false endgame for two weeks every so often while there is still endless stuff for you to earn is completely obnoxious.