I agree with you completely in that many reptiles live in small populations with restricted gene flow, so most problem genes have long ago died out (and possibly some neat animals with them...). However, there is always the possibility of random mutations which crop up and then become far more common due to inbreeding. Not likely an issue in the short term, or even within the span of our lives. Remember, dogs have been 'bred' by humans for thousands of years. So if we talk about the long term, say at least 50-100 generations, there *could* be problems. So if the goal is to ensure that species survive in their present form into the future, why not try to avoid inbreeding? It isn't that hard- just don't repeatedly breed parents to offspring, etc. On the other hand, if one's goal is to produce an amelanistic patternless dwarf morph, go right ahead, but don't pretend to anyone that 'conservation' is any part of what is going on!