Taking a stab at answering my question from last week regarding why for-profit malware developers seemingly have zero interest in Mac OS X, Ian Betteridge makes the epidemiological argument — that malware spreads virally, and thus only thrives with majority platforms like Windows. I think that’s partly true, but doesn’t fully explain the discrepancy as to why the Mac suffers so much less malware than Windows — the Mac has around five percent market share but almost no malware whatsoever.
To be clear, I don’t think there’s any single reason that explains it. I still believe a big part is tolerance on the part of users. Most new Windows machines come loaded from the factory with promotional software that most Mac users would consider adware. It’s a slippery slope to malware adware (as opposed to the non-malware adware that ships with these machines) from there. The simple truth is that Windows users are more accustomed to being annoyed by their machines.
I also think there’s a technical aspect. Anecdotal evidence seems to indicate that Vista really is a lot more secure than XP and older versions of Windows.
But here’s an interesting what-if scenario regarding the epidemiological argument: What if the desktop OS market share distribution were something like 40/40/20 (percent) for Windows/various Linux distros/Mac OS X? Would that sort of heterogeneous split keep malware from spreading even on Windows? Or, conversely, would numbers like that spread malware evenly across the board?