I am sticking to the topic. Which OS do you believe is more secure?
The topic is how many security vulnerabilities exist in various operating systems, NOT how many of those vulnerabilities have been exploited.
The question you pose is a "theory to practice" one. In theory, they are about equal. In practice however, you need to look at how tight the nut is between the keyboard and the chair.
Linux users are usually more computer savvy, so I think Linux is the most secure operating system. Mac users generally don't know or care how thier computer works, but they are also less likely to do things that make their systems less secure. Many Windows users shouldn't even be allowed to own computers. They are clueless to the point of being dangerous.
Anyway, any OS is as secure as the person who uses it wants it to be. Security isn't easy, convenient or fun. If you want to be secure, you have to do without certain things. Add functionality, take away from security.