First consider it from the perspective of a packet receiver for a second (because, among other things, this is how Goog and Yahoo were thinking about it when they supported net neutrality).
-- If AT&T deprioritizes your inbound packets, it's like losing several US states worth of traffic. Your main option: pay AT&T more to prioritize your packets.
-- If Goog deprioritizes you out of their search rankings, again, like losing several states (or countries) worth of traffic. Your option: pay Goog to place you more prominently via AdWords.
> People are free to search with Bing, they are not free to ask that their routers avoid AT&T’s network.
From the perspective of a packet receiver, you cannot realistically make your customers switch from Goog anymore than you can make them avoid routing packets through AT&T connections.
> then anyone whose connection gets passed to AT&T at any point in the routing would be affected, even if neither the provider nor consumer is a customer of AT&T.
Also, a second point: when I make a telephone call to a business, I have no idea whether AT&T dropped the connection or what if it doesn't go through. I just give up on that business and call another business.
Similarly, if a business isn't in the organic top 10 on Goog, I don't even know about it. I just use another business. Note that in this situation neither I nor the business am paying Goog money.
Of course the business can use Adwords, but that's like paying AT&T to prioritize their packets.