Yes, they will leave in droves. So why not cater to them with content and make more sales? Bungie are painting themselves into a corner by making the endgame so slow: most will just leave and the few that don't won't be enough to fund further content. Kind of like what they claim to be suffering from now... All of year one was done in the way described above and even that was pushing their luck. Players will only tolerate so much grind before they leave.