Margin accounts and other strategies that leverage the investments of wealthy people have a nasty way of accelerating losses --and quickly.
A slipping market quickly becomes an avalanche and, you are right, the little guy only has so much to lose. The bigger guy often gets caught up in a multiplying loss situation that he can't get out of.
Having said that, I am not sure if the banks were scared of a decreasing market for Ritz-Carlton's fractional product or just scared in general.
It's interesting to note that despite the Marriott organization's never ending campaign to not use the word "timeshare", nobody ever gets it. Even the financial press is calling this a Ritz Carlton timeshare.