Note that "people" are probably CIO's of Fortune 500's.
As an engineer who was doing programming and systems work in engineering, I evangelized Linux for a decade and a half at a Fortune 250. When someone in IT finally took a look at it, they, of course, demanded that it have a virus scanner. (To be fair, this was near one of the really big Windows outbreaks.) One of the AV companies had actually released a Linux version, so I just calmly told him about it, and stroked his notion that Linux was actually ready for the desktop, even though I thought the whole idea a complete waste of time. In my opinion, cleaning up whatever MIGHT have been caused by a Linux infection would never have been worth the traded performance and administrative overhead of installing it and keeping it updated.
Seems to me that this scenario might be playing out again, as OS X is actually a viable corporate desktop now. Again, I don't think the level of risk warrants the level of cost, but that's not my call. Having a "corporatized" AV (like the Symantec monstrosity that frequently stalls this high-end Dell mobile workstation) is a checkbox that would open the door to corporate deployments of Macs.