Is isn't. Really.

Linux and *BSD systems are fairly secure by design. They default to security over user-friendliness. Sure, there are holes in applications and daemons that are run. But anything public facing is usually run as a role user that doesn't have permissions to trash the whole system.

Windows has always chosen 'ease of use' over security as a design model. And trying to run as an unpriviledged user in windows seems to be an exercise in frustration.