Ahem, not all phone companies have the means to switch from copper to fiber. About the only two in the US you hear about are Verizon (FiOS) and AT&T (uVerse). Some of the cable companies also take this approach with fiber to the node, allowing them to divide neighborhoods and such into smaller nodes that provide more bandwidth between them.
Thing is, sometimes the problem isn't the last mile but rather a different mile: something in the backhaul. That's the kind of problem rural communities have: sorta like trying to connect two four-lane highways with a rickety one-lane bridge. PLUS there's the matter of linking up distant cities since any weak link along the line slows everything along it.