This is probably because requestAutocomplete has been moved into Chrome Beta, and will probably feature tight Wallet integration.
http://www.chromium.org/developers/using-requestautocomplete
http://www.chromium.org/developers/using-requestautocomplete
My guess would be that operating a physical goods processing company is a huge drain on the resource Google hates providing most: customer service.
Payment disputes are a pain, especially for physical goods. Some level of mediation is required when someone has purchased a physical good but has a dispute. But with digital goods you can just tell the seller to eat it (digital good, no actual cost loss)