I don’t understand why there is so many shows about Alaska, honestly I think there is about 5 shows just about Alaska, does anyone else think there is way to many shows about Alaska?
Oddly I thought of Sarah Palin after reading your post. It is weird though. Alaska is a lovely place during certain times of the year but it isnt that great over there 
I think you’ll notice it in spurts and cycles. There might be several shows about Las Vegas and that will go on for a while, then Miami, and God help us…New Jersey etc.
I think it can be a combination of factors. For one, I think a the networks realize that as popular as shows that take place in NYC are, the majority of the TV watching public really can’t relate to the New York lifestyle or mentality, so they come up with shows that take place in other locations in the hopes of capturing demographics they may be missing with the bulk of their programming.
I’m sure on some level the chamber of commerce of the various states might try to encourage such trends as it can effect the local economies on two levels.
First, consider a show like Jersey Shore…these no talent jokes do an episode at a local club that could be floundering and on the brink of bankruptcy and I guarantee it will suddenly become the hot spot for all the local kids to frequent.
Additionally they may have hopes that certain locations being featured in episodes might drum up interest that increases tourism to the area. I’m willing to bet this could very well be the case with Alaska.