I don't have a PhD in anything but here are my thoughts. They don't bond with each other then why would snakes bond with us? I don't see an evolutionary advantage to keeping a emotional bonding in an animal that does not bond with others of it's kind. They are a lot smarter than we give them credit but so are many fish.

Comparing reptiles to birds also seems very apples to oranges. Birds are warm blooded which to me, makes a big difference. With snakes being cold blooded I would think they would use their brain differently.