harping on how insecure linux is implies that if you only avoid using linux, you will be safer.
the reality is that every OS has problems at some point. I don't think that anyone disputes that.
however there are systems that are less secure than others. OpenBSD is one of the better ones (assuming you can actually live with the small feature set supplied)
even in linux distros, there is a wide variety of default security (depending on what is installed), and just about any desktop distro is going to have more vulnerabilities than the server distros. This is in part due to the fact that desktop developers tend to worry less about security, but mostly due to the fact that there is just less stuff installed on the system.