One reason is that we want our developers to be part of a technology community. Attending (and presenting at) industry events, meetups, bar camps, and local user groups. There's a lot more opportunity for that if you're located in certain parts of the country than others.

I'm sure that Buffalo, Oklahoma is a fantastic place to live, but we prefer you be somewhere you can hang out with, learn from, and teach other geeks.

That said, if you're unbelievably awesome, hit me up anyway. We like smart people regardless of their location.