
I am a "Technologist", a Technology enthusiast that is usually the one that is called should a major catastrophe strike an end user. My saga of computer rescues becomes a plot that is ever so thickening, if not only for the fact that's it's becoming incredibly easy for hackers and malicious code writers these days to invade personal property to find, seek, and destroy. Each year, virus and hacker threats increase, and in addition the damage trail left behind is something of a problem. Not to forget, a majority of "PC Panic" cases I've come across are often times the same common, "major" problem.
If everyone on a given network is running the same software, than a single exploit is potentially capable of taking out all of the machines on the entire network.
If one is running a mix of different platforms, the probability of that happening is likely very low.
Maybe more inportant for businesses than for home users, but I'm sure glad I'm running a mixed OS/2, Windows, and Linux network here with the Windows boxes locked tight behind a packet filtering firewall...