Charlie Miller in an interview talks about how Mac OS X is a very simple operating system to exploit due to the lack of any form of anti-exploit features. He also explains that the underlying operating system is much more important in creating a successful exploit than the bowser, why Chrome is so hard to hack, and many other things.
When asked “did you consider reporting the vulnerability to Apple?” He is very honest about this, and says: I never give up free bugs. I have a new campaign. It’s called NO MORE FREE BUGS. There's a market for exploits. "Vulnerabilities have a market value so it makes no sense to work hard to find a bug, write an exploit and then give it away," Miller explains, "Apple pays people to do the same job so we know there's value to this work."