If people were to be lambasted for getting rid of reptiles and amphibians, how many of the people on this forum would fall into that category?
As long as a herp is well cared for and treated with respect, there's no reason to see trading or selling it off as such a negative thing. I believe they're qualitatively different from say, dogs and cats.
Although I agree that plenty of research and foresight would cut down on the 'revolving door' thing you seem to be referring to. As an exception, the only thing that bugs me is crocodilians and chelonians.
I think too many people think they're going to make a big commitment to animals like sulcata tortoises and caimans, without taking into account things like:
a) specialized dietary/environmental needs
b) huge requirements for space
c) long term suitability