Why is captive animal release so hard?

* It focuses on a few, charasmatic endangered species * genetic diversity may have sunk too low to be regenerated * costly, diverts resources from much more cost-effective ecosystem and habitat conservation measures * gives false sense that battle against extinction is being won * what if the habitat no longer exists, or cannot be expected with any confidence to exist in 200 years time. What point then ? * NRE 220 students often react negatively to the degree of handling/intervention associated with captive breeding, and apparently would prefer to see species go extinct. Really?