William Weld Running For Governor of New York?

I was surprised to read that former Massachusetts Governor William Weld is now running for Governor of the State of New York. I find the "transient" candidates -- particularly for statewide offices of Governor and U.S. Senator disturbing. For example, U.S. Senator Hillary Clinton from New York lived virtually all here life elsewhere. How can she represent them? Why can't the different states simply elect someone who has always lived in that state their whole lives? That would be the best kind of representation -- not this transient stuff.