I agree with @dioxide. People buy developer for several reasons:
1) Confused by a complicated product. Lack of awareness. Little research on more cost effective alternatives. Painful but won't bankrupt
2) Fear of getting scammed. Fueled by scams by the timeshare exit teams and on Ebay. At least you know your product is legit from developer.
3) Professionals with plenty of money, Don't have time to look for deals. No desire to try.
4) Cannot afford. Gullible. Should not be considering a timeshare.
Some developers are differentiating their product with access to elite, more resort booking options and flexibility. For example, MVC with non-enrolled resale, HGVC lack of access to elite, Vistana voluntary, Disney Riviera. Some people value those choices just as they would a new car versus a used car.
When I met with some elder law attorneys, I was shocked to learn they had purchased Marriott points from Marriott in large enough amounts to keep them in vacation mode for years. They were so happy with their vacations, I never said anything to them about it.