Blizzard do care and they have said times and again that alts are ok but are intended to be less powerful than mains. Intended, as in "by design" less powerful, as in constraints are explicitely setup in the game to prevent limited alts from getting as powerful.
So account-wide Pathfinder is intended, but rk3 essences and mythic gear on limited-playtime alts are not. Hc gear and rk2 are really fast to get though, no excuse here.