And honestly I can understand why! Let's look at this from a complete point of view from somebody starting now! First you have the 1-60 experience that doesn't make much sense unless you played Vanilla, TBC and Wrath. 60-70 you're thrust back in time with no indication that the events from here on are set before 1-60 experience (same with 70-80) then your back to the timeline in 1-60 (again not mentioned)
I understand it is kinda inevitable that Cataclysm fucked up the chronological order of the levelling story experience but I have had a few people just quit because the story made no sense without background checking everything