Who said ANYBODY buys "every single R1 release?" I sure don't, and I don't know anyone who does or who could afford to. I only buy series I liked well enough to archive the fansubs of. That leaves plenty of series I watched before it was licensed (some of which I actually finished), but didn't buy once it was.
For what it's worth, I seriously doubt that this is a significant trend. Unless the prices come down quite a bit, I fail to see how shows like this can POSSIBLY be profitable when compared to the traditional TV-then-DVD/BD approach. Like you say, very few people are going to buy this stuff SIGHT UNSEEN, at $4/episode, for a temporary copy. That's VERY different from buying a DVD release of something you've already seen (and liked), at similar prices, for an essentially permanent copy.