If more of the gated systems are made account-wide, would that not make players want to play alts with the incentive of progressing whatever this account-wide system happens to be? For example, make system "A" account wide, make it so a single character can only do it 3 times a week, but progress is account-wide.
If I have 12 alts/different classes at max level, I get to repeat the same gated-grind 12 times x three a week. Would this kind of design make gated systems feel like a win-win where players are happy their progress is account-wide, alt friendly and not boring since the player gets to play using different alts/specs/classes...etc?
This can't burn out players if the grind takes 10-15min and is limited to once or twice per WEEK per character. Let's say you have all 50 alts max level, which many altaholics already do anyway. 50 times 10 minutes divided by 60 minutes equals around 8 hours per week which is a little over an hour a day.
In Shadowlands, leveling an alt from 1 to 60 will probably take half the time it takes to get to max in BfA. Alt friendly systems and account wide progress is what you all want, right? That's the win for the players, and the win for Blizz can't be even more obvious than that.
Another option would be to let players do all the above 8 hours worth of grinding per week on a single character (main) if they want to bore themselves to death. That way, nobody can complain about being forced to level up 50 alts.
But then again, Blizz probably thinks most its players are dense and troubled addicts, so they will just do what they think is OK regardless of feedback.