Remember that the Marriott program is essentially a frequent flier mile type program. As noted, you don't get that option unless you pay the big bucks through Marriott, even then, it truly benefits a precious few. Under the old program, it benefited those that had other sources of Marriott Reward points and were willing to take a trip half way around the world about every 2 or 3 years. Personally, I never saw that portion of the program as reasonable. The fact that they can change the program at any time (and have recently for the worse), is a large detriment. They could do away with it also, though I suspect they won't. To me it's much like the Concierge collection, nice to have options, but oh the cost.
The best Marriott values don't come with points in most cases. I bought 2 Marriott weeks. One was not qualified for the points because it doesn't come with the property in question, the other has points for the property but I bought resale and can't get the points. The $8000 I saved on the week at Grande Ocean more than makes up for not having access to points exchange.
I love Marriott for different reasons. They have great resorts, in great places that I like to go. They have internal trading to the other Marriott resorts (more than 40 now) and good to great trade power in general. I believe a Marriott ownership compliments DVC nicely. For another timeshare purchase outside DVC, what's best for one is not what's best for another. In general, I'd buy either cheap or something I'd use (or both). Partly depends on what you want, where you want to go (and when) and how flexible you are. Remember you can always trade or rent if you want.