Earlier quoted context omitted.
http://www.computerworld.com/s/article/9129978/Researcher_cr... Mac isn't significantly more secure. In fact, after all the bad press, Microsoft has invested significant amounts of money on intrusion mitigation systems like address space randomization, non-executable stacks, and so on. Linux is playing catch up to Windows in some regards there, and from what I know about OSX, it's also far behind in intrusion mitigat…
Uh, citation, please? You liked to an article that says "there once existed a vulnerability in Safari" and then right away claimed that Linux and OSX are "still catching up to" Windows in terms of security. Now, I want to believe you, but it sounds to me like you're speaking with a little too much conviction relative to the evidence you're presenting.
http://web.archive.org/web/20080111062141/http://www.matasan...
Another (fairly poorly written) article about it: http://www.tomshardware.com/news/hack-windows-security-snow-...
I'm sure you can find more if you dig around.
Also, non-executable stack has been supported OSX since it was shipped, but non-executable heap is new. I believe (I'm not sure) that non-executable stack is also disabled fairly often because of trampolines in GCC.
Security in OSX isn't broken, of course, but the mitigation measures are strongest in Windows, out of the mainstream OSes these days.