What might hurt things is that the redemption value for vacationclub owners exchanging their week for points has declined substantially over the last several years due to devaluations in the marriott reward points.
Marriott hasn't changed or increased the number of points they will give for exchanging your week, but you get a lot less value for it. For example, 5 years ago say you could exchange your Hilton Head property platinum week for 110k marriott points. That could get you a decent stay at a nice hotel. Now with higher categories and everything moving up, you still get the same 110k points for your week but that is now only enough to stay for a couple days somewhere instead of a week. Hence a lot less people are trading for points and so there are less weeks open for points redemption.