To be fair, almost all of the proclamations I see from people about Windows being insecure are based on old, pre-SP2, pre-SDLC anecdotes and experiences (which were definitely true at one point, but haven't been true for quite a while).

It would be like if I railed against Linux being usable by complaining about how bad the sound subsystem was...

This Usenix video from last year of Crispin Cowan going over improvements to Windows security was interesting:

http://www.usenix.org/multimedia/sec10cowan