Not all owners who walk away own dog weeks either. When our resort rebuilt, we were able to reassign units, and eliminate a few precisely because the HOA endud up owning enough of EVERY week to do so.
When the timeshares were sold, the owners of those dog weeks paid much less up front. Yet, if the timeshare program were to be dissolved, and the resort sold, they would be entitled to an equal share of the profits from the sale. The issue is that there are two parts of a timeshare ownership - who you OWN based on the deed, and what you are entitled to use (also listed on the deed, but not truly relevant to what you OWN.
Take a typical 2BR condo on the beach (in a very seasonal area), with a market value of $200,000 if sold as a whole-use condo. Instead it is owned by 50 individuals, each assigned a different use-week, with 2 weeks used for maintenance. When sold by the developer, the best summer weeks were sold for $20,000, the low season was sold for $5000. They each paid $5000 for their ownership, and the peak owner paid $15,000 extra for the right to occupy the best week. If the condo is sold today for $200,000 each has a right to $4000.
Those same weeks may sell for only $1000 on the resale market today (if not less), but the underlying value of the real estate is $4000 per week.