Wyndham has been worth pennies on the dollar in the secondary market for almost as long as I've owned it--well before most of the moves Wyndham has made to curtail renting. And, that's probably not surprising, because for most people the value proposition is not in renting, it is in the using. Yes, a number of people have left (or been pushed out of) the rental business, but that seems to be on the margins of the overall market as near as I can tell.
Wyndham is worth very little on the secondary market because (a) timeshare is a product that is sold, not bought; (b) Wyndham's brand value recognition is not worth much compared to the majors; and (c) the system is huge, so at any point there are plenty of people looking to exit.
No one is going to get excited by the company that brought you La Quinta, Ramada, and Baymont. Those don't even rise to the level of your average Holiday Inn---and that's already low rent. But the WVR resorts themselves are generally very good, they are often in attractive locations, and the ongoing costs to own can be very reasonable. So, if someone can get past the "sold not bought" barrier and has some understanding of the portfolio, it can be one of the better values in timeshare ownership.
You don't need to own a developer account for this to be true. In fact, I suspect for many families' use cases, VIP is more or less useless. That's because they are traveling to high-demand locations at peak times, and those are not the sorts of reservations that are sitting around at the discount window. Upgrades are likewise not particularly helpful. If I need a 3BR, I'm not going to book the 2BR and hope I get upgraded. I am going to book the 3BR from the start. If I only needed the 2BR, maybe the 3BR is a little better for me, but maybe it makes no difference at all. Yes, you can probably find instances of people who can do most of their travel in shoulder seasons and make VIP hay, but you need an awful lot of those reservations to make back the difference in purchase price. When it comes time to dispose of it, even if you give it away, who cares? You paid next to nothing for it in the first place.