Agree with this.
I also think there is (should be) a legitimate concern within DVC as to whether this provision would stand up to a legal challenge. While many would argue that limiting rentals serves a greater good, we're talking about a large corporation trying to dictate how customers can use a very expensive product. Just because DVC wrote this vague language into the contract prohibiting "commercial rentals" doesn't mean that courts would agree that Internet rentals or 20+ transactions per year are a reasonable test. They may find that Disney has absolutely no right to prohibit owners from selling points after purchase.
Or they could go the other direction and uphold the clause, while expanding it to include Disney's own commercial point rental activities. This could potentially leave Disney unable to use its own point holdings to sell villas to cash guests.
DVC could consider some across-the-board policy changes which are designed to limit rentals. But there would likely be fallout for all members. For instance, if they tried to limit changes to the names on a reservation to avoid spec rentals, it would impact all of us whenever we need to make changes to a traveling party.