What do you think has the greatest possibility of keeping the most players playing longer/longest?
The route they've gone:
Making a given player and subsequent character required to have huge grinds, AP, rep, honor, etc.
The route they abandoned:
Alt friendly. 1 of every class ready to fill tonight's empty slots.
Personally I like alt friendly. Honestly if I am playing a few hours a day, and paying for those hours... why the fuck does it matter to you (Blizzard) whether that is on multiple characters or a single character?
A couple of points:
(1) Despite Blizzard's "commitment" to maintain balance (both PvE and PvP)in Legion they are still doing a pretty shitty job. Underperforming classes remain underperforming, and the most powerful stay at the top. There definitely isn't any sort of sense of urgency to get things corrected. Having alts means I don't have to put up with being last picked or least desired because the class I chose... sucks.
(2) Change of pace. Sometimes I want to play something else... not because it sucks. Not because the game sucks... but simply because I want variety. Look at any of the tournaments. They are given multiple fully geared characters to choose from, or switch out if needed (teams rarely do). But that isn't reality, most players (especially in Legion) don't have multiple characters anymore.