Mac Os is Unix (not Linux) based which can be developed in any way shape of form. Some of the worse OS’s I’ve experienced are Unix, but they can also be some of the more stable a secure - all depends on the application. No OS is void of malware, and Apple is not an acception to that rule. True more virus are developed for Windows based PC, but that is strictly due to sheer numbers and not because they are more vulnerable. That said, Windows security when it comes to malware can be argued as being a better platform given the many technology partners involved. The Flashback virus, which exploited a Java vulnerability was not OS dependent. Microsoft worked with their tech partners and a patch was quickly developed thus stopping the spread. Apple does not use native Java, but their own proprietary version that is still based on the Java core and still susceptible to this virus. They insisted they were to develop their own patch, which took months to roll out. Damage was already done.
Driver support is much the same. MS relies on the hardware vendor to provide driver updates outside their native drivers within the Windows OS. Apple consults with the hardware vendor, then writes their own drivers and includes them within the OS – updates come in the form of patches or a new OS but are slower to roll out than Windows. Both environments have their pro’s and cons. Personally, I prefer to control my hardware drivers. But that is me!
Part of my profession involves vulnerability management which includes access to industry databases, some unknow to the public. Throughout the years, the common trend was Apple Os X had more vulnerabilities than MS. Lunix (in its many forms) was even higher. That said, detailed analysis is needed for they are scaled based on execution and severity. And given both OS’s must use the Intel x86 architect, hardware vulnerabilities can be the same across both platforms. But in a nut shell, Apple is no more secure than Windows – what is key is correcting these vulnerabilities before they are exploited. Both companies do a fair job at that.