I saw several. 1. Single point of failure/control 2. It's a retraction from the web's inherent uhhh 'webby' nature where you can link to any content. 3. Google

I saw several. 1. Single point of failure/control 2. It's a retraction from the web's inherent uhhh 'webby' nature where you can link to any content. 3. Google wants to become a 'toll booth' on the internet where it inserts itself between users and content. As an aside, I think people do sense a bit of hypocrisy from a lot of "benevolent" companies like Google. They're all open and standards-y when its about commoditizing a sector in which they don't have any direct financial interest. But they're fiercely closed and proprietary when it serves their interests.