1% (it's actually more like 3%) of the worldwide market share is still a **** load of phones. But I understand what you're getting at, and while there is more money and marketshare to be had on the low end, none of those phones make headlines and turn heads like a flagship phone.There is little (if any) money to make in the Windows Phone business. Why would a business throw millions into developing & marketing a phone that less than 1% (considering most of WP market is low range) of the world would buy? The only reason HTC gave us a "High End" device is because it's the same hardware as it's Android flagship --- and this only happened because Microsoft modified its hardware requirements to persuade them to do so (on-screen buttons & no more required physical camera button).
It's only logical that they get in on the low-end range...the only place Microsoft has seen success.
And how much more money does an OEM spend if there is already an Android version of that phone already in circulation? I'm surprised that HTC (and to some extent Samsung with the Ativ S) is the only one who has done it. I don't see it being a financial burden. With that said, at least we have some proof of what many of us thought before when comparing OS's on the same hardware:
Acer Executive Says Windows Phone Runs Better On The Same Hardware Than Android - WMPoweruser