Read again please....
If more people end up disappointed than happy, they may choose to drop the program, it being more bother than its worth. In which case it wouldn't be disappointing most to keep a few happy, it would be disappointing everyone for a brief period of time to keep on going complaints down. i.e. If 100 people a year currently scream to DVC about not being able to switch, that's fine. If its 40,000 out of 80,000 members, that's a problem. Change the terms (as per contract) and you'll have 60,000 people scream very loudly for a year, then have a couple thousand never let go - but it's better than the 40,000 every year.
These numbers are, of course, ridiculous, and only used for purposes of illustration. But someone asked why would they. This would be one reason they might.
They might choose to do something like this if a very popular resort were to open - say VCR - that everyone wanted to book and never left its honeymoon period - especially if they didn't balance points. 80,000 people yelling at you every year because they wanted to book the Contemporary but it wasn't available wouldn't be a pleasant customer service situation.
I'm not saying its better. Although, if your short term screaming outpaces your longterm screaming, it is (see OKW pool slide debate).
And, while I don't think online reservations are anywhere as close as six months down the road (although we should be able to see our point balance and maybe do banking transactions in that time period), I also don't think administering resort swapping would ever get so expensive as to make it sensible to drop in. Once again, an extreme "what if" scenario.
I have been informed that this is impossible but if DVC were to sell off some resorts but not others (for instance, VB and HH - or even OKW or sell BW and BC to the Swan/Dolphin folks, or something) those resorts would no longer participate in swapping. You would still have your ownership, but only in your home resort. During the Comcast discussions, the possibility that DVC would be divested was brought up. That's always a possibility, however remote, even if Disney continues to be Disney. A new owner may not choose to maintain the program.