I find parts of the original post wonderfully ironic.

First, the poster notes that his mother's PC was infested with spyware and other nasties. Then he notes that software installation on the Mac requires more work than it does under Windows.

These are two sides of the same coin. If it's trivial to install software, then spyware will also be trivial to install. His mom's PC didn't get that spyware by itself...his mom installed it (deliberately or otherwise.)