I must respectfully disagree with you. I have been a member many years, and a long time ago, worked Mbr Svcs. If your home resort is at OKW or SSR where there are a lot (relatively speaking) of GV's, I'd agree for most times of the year. But for BW, Vero & VGF, especially at busy times of the year, one would want to be calling in at first possible moment to ensure booking a GV.
OKW' GV's are a very good value points wise, with SSR following. It's a supply vs demand thing. Both these resorts are huge in comparison with all other DVC resorts, except Aulani. (And btw, I've been in their GV's, and they are incredible! Really pricey on points, but ROCK STAR!)