Matt, I disagree with your statement that:
"I think the real issue here is that 99% of private collections are more diverse and contain rarer species than are held in the zoos."
Near or next to impossible.
Maybe more diverse due to the availability of reptiles today, but not rarer!(due to U.S.D.I regs).
For example, how many "privates" that you know have Crotalus unicolor here in the states? How about San Francisco Garters, Virgin Island boa's, Komodo Dragons, and a myriad of crocodilians?
The list goes on and on. Diverse, probably, but hardly rarer!
As you know, I am a zoo keeper and I have a private collection, but I DO NOT support ANY ban, from ANY state, that considers an out-right ban of reptiles, be it venomous or not.
Randal