when these malcontents decide that linux users would be more fun to annoy, then that os will be the victim of attacks.
Probably - no OS is bulletproof. But it won't be nearly as easy. It's the difference between what an average bored 14 yr. old can do in a few hours of messing around and what would take skilled programmers a few weeks of work to do.
However, the second reason is that Windows is built like a sieve. MS built DOS and Windows to be as easy to use as possible. Most users are administrator-level users so that they can administer their own boxes. As a result, any virus that gets on a Windows box is also likely to have administrator rights.
Linux is not designed that way. The average user only has the rights explicitly granted to that user or group by the administrator, and virtually no Linux user/owner uses the administrator account for day-to-day activities. Hence, any virus that may get on a box would have nowhere to go as it would have no rights within the system. This design was done on purpose, as Linux was designed with network computing and security in mind, while Windows was designed with single computers and ease-of-use being top priorities.
That is why I say that Linux will never be the vulnerability magnet that Windows is--no matter how popular it may eventually get.