The argument between which platform is more secure is an ambiguous interpretation, and always someone’s selective measurement. No platform is more or less safe than its competitors, and it simply comes down to individual security hygiene and their level of security knowledge.
If you’re one of those people who sees an 80% coupon in your email box and then click on the link(s), chances are you’re getting malware installed on your machine, in essence, an infected machine. This has nothing to do with Mac or Windows; it was simply someone being naive not to review the source URL and know it was a scam.
The revolving argument of which platform is more secure in today’s marketing boils down to end-users acuity on security. Unix-like machines, for example, Mac, Linux, and Android are gaining more market share, which means more attacks on these machines will naturally go up. The bad news for Microsoft, they’re losing hold on the market they once dominated. However, both Mac and Windows will have the same problems, which are end-users not recognizing security threats and understanding best security practices.