For differing viewpoints on inbreeding, check out the thread "Pro & Cons of Inbreeding" in the Elaphe guttata guttata forum.
You'll always get "words of wisdom" from those that are virulently opposed to inbreeding under any circumstances, and they'll assure you that nothing but bad can result from it. Sometimes, you need to just take the words of the doomsayers with a grain of salt. Do it once, and see what happens. If the parent stock are both healthy, and are free of fatal genetic recessives, then their progeny will also be healthy.
The great thing about captive breeding, is that you control the pairings, so you can breed out unwanted recessives, if that is your goal.
"Nothing is so firmly believed as that which we do not know."
<i>H. L. Mencken</i>