It hasn't been shot down at all. There's virus protection for BSD systems, which would be totally unnecessary if Mac OSX and BSD were immune. I know; I run BSD networks at home and work.
But then again, I've never had a virus problem on Windows.
Sure... there are companies making virus protection software for Mac OSX as well... and it does a good job of removing WINDOWS viruses from email and it will also identify WINDOWS viruses in WINDOWS executables... and they have definition files for the fewer than 100 virii that could infect a pre-OSX Mac but that have no impact at all on an OSX Mac. These Mac anti-virus apps also a couple definitions for the one or two "proof of concept" Trojans that were created for OSX by the Mac anti-virus publishers (but never found in the wild)... but the only Mac users who run them do so as a courtesy to their WINDOWS using friends to catch an occasionaly WINDOWS virus laden email they might inadvertently forward to them.
In other words, 1L, I could put up anti-zebra umbrellas over my garden to protect my garden against zebras falling from the sky, but the mere existance of my ant-zebra umbrellas is no proof that there are zebras falling from the sky.
Did UNIX have malware? Yes. Is it a problem today? No... because the vulnerabilities of the open source code were closed almost as fast as they were revealed. The protections against those malware are now incorporated into the underlying operating system. This development and hardening of the OS has been going on for over 35 years.
Is Windows still vulnerable to most of the 100,000 plus viruses that were created to plague it? No. Protections for 95% of those are also now built into the OS... but it it TOO EASY for a script kiddie to write new malware for Windows
But then again, I've never had a virus problem on Windows.
You know, I have Windows XP machines running right here, and I also have never had an infection either... but my business clients certainly have had and do get infected (Fewer now with XP, but I will be busy this week applying patches for their Windows machines for this exploit... and then go back and reactivate the stuff that gets turned off when MS finally gets an official patch out). You and I know what to do and what not to do to keep our Windows machine's clean... but the malware is not a problem for users like us... it is a problem and a fear for Mom and Pop and 90% of the rest of Windows users. A lot of those Mom and Pop users have given up and packed up their computers and stuffed them in the closet or given them away in frustration.
I also have Mac users in businesses and I have NEVER had to clean spyware, adware, or viruses off of even one of their Macs. They lose no productive time to the myriad issues that can plague a Windows box... they don't even have to let their machines download, install, and run updates to the non-installed anti-malware applications they DON'T HAVE TO RUN... and they don't have to accept the performance hit that all those multiple anti-apps demand from their machines when they are running. I get called in to see the Mac users only for upgrades and an occasional hardware problem. If they had Windows computers I would see them a lot more often and make a lot more money from them.