The state that you belong to means much more than random "happenstance." Roads, education, welfare, etc. -- all the boring stuff that government spends most of its time managing -- are all tied to the state. Those are the interests that you have in common with everyone else in your state, and that, I believe, usually overshadow or at least equal your interests associated with other groups. Where states are not bound by common interest in important areas, they can evolve by splitting/realigning (West Virginia did this; California sometimes talks about it).
Whether these regional interests really outweigh interests associated with other arbitrary groups is open for debate. I think they're at least on a similar level -- in any case, like I said, preventing abuse is hard enough when voting is based on residency; doing anything more would probably be unenforceable. And I think it's essential that some measure of broad appeal, beyond strict popularity, be used in the formula that determines which candidate is best.
The discussion of rural states was just an example. I'm not suggesting that "rural" people deserve special treatment. I'm saying that small states, despite their small size and regardless of their demographics, deserve to have their interests as entities represented.