The End User Keyclick.
Linux is just as vulnerable to "click here for your malware embedded e-card/tax return/bank warning/cute puppy" type attacks. For that reason, even Linux users should still run a scanner.
Also, depending on driver support for your hardware, Linux can be "klunky" too. Win 7/8 run a lot better than their predecessors. OSX Snow Leopard/Lion run well on newer hardware, but bog out older Intel iMacs.
Too bad Mac's idiotic EFI won't let me drop Linux on those old Intel XServs. Even with rEFIt on it. The hardware would be perfect for running a VM cluster.
Have you seen this?
You are mistaking an attack on the Web browser with an attack on the OS. The unix OS is safe from attack if the attacker does not have the root passwd