Not true at all. Please read through their stance on requirement of antivirus on the machine in response to flashback Trojan [1]. Instead of arguing against or for Antivirus, they are blaming windows.
" Do I need anti-virus software?
Ah! The loaded question. That's up to you. To date, all of the Mac anti-virus software still checks primarily for Windows viruses. The anti-virus companies have literally stopped counting how many Windows viruses there are. The Flashback trojan didn't even qualify to be called a virus. Still, all Windows users run anti-virus software. The only growth opportunities for them are Macintosh and Android. Expect a hard sell. Nothing sells better than fear. My advice? Be fearless!"
For hacker news audience ,who can take care of their own security, antivirus may just be snake oil but for clueless end user it is a big help.