Saying what has (or rather hasn’t) happened in the past makes no sense
From a Windows perspective, I’d concur.
1) Most of the propaganda may be true of XP and older, but NT6 core OSes are a different animal. It’s simply disingenuous to tar current Windows systems with the same brush as a ten year old OS.
2) The vast majority of infections these days are exploits in third party applications (Flash and Java predominantly) and not the core OS. The other big security flaw is the user; if people intentionally bypass security by allowing malicious software to run, there’s not a lot you can do about that.
A bit of common sense goes a long way. The last virus I was affected by was on Windows 95 and I can’t remember the last time I got an alert from MSE; it’s in the order of years. If you habitually torrent cracked software and surf dodgy porn sites, ultimately you’ve only yourself to blame when something goes wrong.
3) There are of course considerably more hostile programs aimed at Windows. This isn’t because OSX is inherently more secure, but a simple economy of scale. PCs outnumber Macs ten to one, if you’re a virus writer then which platform are you going to target to reach the largest audience? And arguably, which platform is likely to have the most non-technical users who are going to be fooled by scam emails?