I think there is a big difference between a realistic and minimalistic nationwide permit system for venomous and perhaps a separate system for large constrictors, and the slippery slope of banning all of our pets.
The state of Florida is a prime example, they've had a proper permit system in place for some time now.
If the responsible owners have no way to differentiate themselves from the people who are doing it wrong, I believe it will be a lot easier for them to get rid of them all.