Second, my Vudu library contains over 600 movies and significantly more television shows than that. And before you calculate the cost of the storage, bear in mind there's another, secondary cost: The much higher cost I'd have spent to have built that library solely on ripped discs. I never paid full price for a digital purchase. (And specifically, never more than it would've cost to acquire it via disc.)
Third, time. I'm also significantly backlogged in organizing my ebooks, which I do store on drives. Blu-ray ripping time just isn't something I want to dedicate a big chunk of my life to.