Because I read this guy's review: http://maddox.xmission.com/ and before you flame me, yes I fully understand that he's reviewing the 1G iPhone. Still salient points to be found within.

And yeah, I absolutely despise on screen keyboards too. I like the tactile feedback so that I can type without having to stare at the screen.

I got hooked on WinMo when I first switched to my very-soon-to-be former carrier, Verizon. Their proprietary UI stank, and was was wayyyyyyyy counterintuitive (I was migrating from a sidekick 3, which I still somewhat miss to this day, best hardware KB I've ever had) Now I can't imagine anything else in my hand. I write and post to discussion forums a lot, and I couldn't do it without WinMo, even as wart-encrusted as 6.1 is.

Also, AT&T's rate plans are usurious, and their coverage sucks where I live. I constantly get the few iPhone users at work (which involves some pretty remote field assignments in Arizona) asking me "You get reception here?" which was honestly the reason I switched from T-Mo in the first place, as my plan pricing was ludicrously cheap (sidekick data grandfathered at 9.99/mo).