Well, O'Reilly seems to be focusing on the large, corporate market, with a broad array of topics, so from that perspective this move makes perfect sense as a small, simple optimization on their part.
At Pragmatic Bookshelf, however, we focus on the individual, highly skilled developer looking to improve their skills and those of their teams. We don't offer a broad array of tech topics, just the ones we feel are important.
We focus on readers who like to collect and own their books, DRM free in epub, mobi, and PDF formats (you get all three for one price, and can re-download forever, or as long as we're in business ;)
It's a different market, and a different approach.
So don't go hating on O'Reilly for this move—if it doesn't suit you, you're not their market. And that's okay. It's a big world.
/\ndy Publisher, Pragmatic Bookshelf