If they offer below-market (for American workers) salaries and get no sufficiently-qualified domestic candidates, as they're required to promise they do, it's no surprise to anyone that they're hiring a ton of H-1Bs. They want that because they want to pay less.
I don't blame them for doing what's fiscally advantageous for the shareholders up till now -- but I think I'll be glad to see this change implemented, if it is, because I know companies write on those forms "domestic talent not found" when they know the truth is "domestic talent not available at the wages we'd like to pay".