While it is true that they were generally less prone to malware, that was not due to inherent security features/improvements over Windows, and was instead mostly function of the relative obscurity of the platform. Can't get a virus from a downloaded game, because nobody makes made games for that platform.

In every lab with students, all machines were regularly b0rked and when I say regularly, I mean monthly. Complete re-imaging of 200 machines every weekend ended up becoming the norm because the techs couldn't deal with the endless destruction.

It was really a matter of the platform having very little saturation in the market, and therefore less malware existed for it. However when in an environment with mostly Macs it was a shit show.