Except that there is never going to be an open source jailbreak. If it were open source, then Apple would be able to easily see what exploits are being used and patch them. In the past, has there ever been an open source jailbreak?
Apple will find the exploits for binary-only jailbreaks, no problem. Also, there's been several source code releases for jailbreaks before, like https://github.com/comex/star_
The details of exploits used in jailbreaks have typically been released [0] or reverse-engineered [1], so open-source or not, Apple will typically fix them in the subsequent release.
