It would be more fair to criticize the corporate culture at Microsoft in the 90s that led to this situation. They simply didn't really care. If another OS was

It would be more fair to criticize the corporate culture at Microsoft in the 90s that led to this situation. They simply didn't really care. If another OS was dominant, it is easy to argue that fundamental security issues could have been addressed in a better fashion, if management wanted it to be so. To wit, this is the same era of computing that spawned OpenBSD. You can't say with a straight face that OpenBSD would have been brought down by oversized ping packets or be allowed to accept traffic out of the box like Windows was.