Anyone remembers Titanic ? I think computer security is little like that. You get vulnerable when you think you don't need to care. Some OSes or platforms are more secure simply because force you to use secure practices (remember UAC on Vista). Modern platforms have been designed with security issues already learned and fixed, so it has little sense to discuss the security on platforms as something inherent to the platform. The approach is taken from the user point of view (tell what you want about Mac / Linux lacking AV, but Windows relied on 3rd party software...). I agree that the number of threats relates to the number of users, but security has to do with your own practices and not the platform itself, because sometimes the security flaw comes from social engineering (guessing your password, etc...). Don't want to take out the guilt from adobe, they need to fix that. invent is always easier and faster that the society adapts to the invention, this has to do with human nature and how we will use the invention, just some little time to get our habits clean and safe (as we do with our house keys).