My sister and BIL (who love Disney, and are child-free) have a DVC, and are considering upgrading to a larger package because they can sell the additional points for more than it costs them to buy. No idea on the details, but they are generally savvy enough that I believe them on this.
Also, my parents have timeshare. I guess it's more of a "club" in that there are multiple (probably a couple dozen) resorts from which to choose and they can go any time. It's actually be a wonderful things for them and they have more than gotten their money out of it. I think they have missed one year in about 20. Our family vacations together (parents, 2 adult children and spouses) as often as possible, and many years extended family and friends are invited. They timeshare allows my parents to book additional rooms for friends for pretty cheap, so people are often happy to get a cheap vacation, and it has created many wonderful memories. Some years we had 20+ people.
I think it is the flexibility in time and location that has made it so great for may parents. They own a certain number of years, but can also pull years forward in case we have a crowd. The "own" at the level of a large suite, or they can take it as 3 regular rooms, so they can pull forward a week and get 6 rooms, or book friends under "bonus time", which is maybe 50% off the regular hotel rate.
They just got back from a week in Cabo San Lucas and are headed back to Mexico in a few weeks with my sister and me and our husbands. My parents are extremely frugal so this purchase was way out of character for them, but I'm so happy for them that the did it, as it has been a very good thing for them.
I would never buy a timeshare, but I don't think they are always a horrible idea for everyone. I would never sit through a pitch though. I am super uncomfortable with that kind of thing. I'm a terrible haggler, and I put it in kind of the same category. I could probably say no if I had to (and when tens of thousand of dollars are on the line, I'd have to!), but it would be super painful to me. Part of the joy of begin financially responsible is, to me, not having to do stuff like that to get a free meal and a night in a hotel. I'd happily pay for that if I wanted it, rather than *earn* it doing something super unpleasant for me. But for people more assertive, I can see why it is worth it.