Being honest - Linux is dull.
My Dad used Linux, and wears his penguin t-shirt to this day. But let's be honest, it's getting dull, no new infrastructure innovations in years (and "Red Hat" isn't an innovation, it's a distro). While Sun has started creating some extraordinary new ideas and technologies.
So my Dad can keep flying the penguin flag, along with all you folks like Matt. Me, I just want to get my work done faster than last year, not fight some freakazoid license war. OpenSolaris looks pretty slick to me.