(Warning - conspiracy theory alert!)
It's hardly "equal opportunity" when you compete against a computer that also controls hundreds of weeks at the same resort and books them all consecutively or concurrently in a fraction of a second. The problem may routinely be the Abound system booking instantaneously at 13, 14, 15, 16 or 18 months out and locking out owners. Then MVC can conveniently blame the "mega-renters".
I obviously only have circumstantial evidence, but I routinely have problems getting a Saturday checkin for some weeks when I try to book them at 14-15 months out. Given that half the weeks inventory is supposed to be available at 13+ months out, I always find it very hard to believe that so many other owners (it's a very big resort) are that diligent.
Since this is the Vistana board, I'll just elaborate that MVC weeks reservation rules allow owners to book 2+ week consecutively or concurrently at 13 months out (they do not have to be at the same resort). An owner who owns multiple weeks can book the first at 13 months out, the second at 13 months + 1 week, the third 13 months + 2 weeks etc and can also book multiple weeks concurrently at the same time. So, an owner (or Real Estate Trust) owning 10 weeks for example, would be booking the 10th week at 15+ months out. I annual personal experience is booking several weeks in a row with a Saturday checkin and then when I get to the 4th or 5th they tell me "sorry, I only have Sunday or Friday". I obviously always call at 9am at 13 months out to book the first week, and booking via phone is the only method for owners to book at 13+ months out. While those are competitive weeks to get, I've always suspected the lack of Saturday checkins that far out has to do with Abound eating up that inventory somehow. I find that more credible than the explanation that hundreds of owners beat me to it.
Now imagine that you are a real estate trust that owns thousands of weeks at multiple resorts, or maybe it's exchange inventory from owners who deposited weeks way in advance, and you get to use the 13-month rule to book all the weeks you control consecutively and concurrently (remember that to use this rule the weeks don't even have to be at the same resort). What can possibly go wrong for other individual owners?