Huntington's residency requirement

Something I've wondered about this weekend:

You don't have to be a Cabell County resident to be employed by the Cabell County school system. I've met Cabell County teachers who live in Ohio, and I've met some teachers in Ohio who live in Cabell County,

I'm pretty sure some Marshall professors live in Ohio.

As far as I know, I could live in Ironton and commute to work to my state job in West Virginia if I so desire.

So why should someone who works for the city of Huntington have to live in the city?