While I agree that MS products do tend to have some glaring security issues, I doubt this would be alleviated by other OSes if they were in the position Windows is today.
Linux tends to be more secure, becuase it isnt as well known, and has only a fraction of the user base. If things were switched around, I'm fairly certain Linux would have more than its share of headaches. Malicious hackersare obviously going to go after the larger denominator, because its more likely to succeed on a larger base, and because home users arent likely to know as much about security as the Linux base, since you almost need a degree in computing to even get Linux to run properly.
Frankly, these things are bound to happen, because the consumer requires more and more features as time goes on. Adding more features will almost definitely lead to more bugs, including security leaks. While MS may be biting off more than it can chew, I dont know any other company out there that can do the same job any better. Tell me of one company that can, and I'll eat crow...