For starters 802.11 has finite power limits, which means you need about 7 to 9 base-stations to cover a single mile versus the 1 of 700MHZ LTE.
Even if they could boost the power, it would kill off home wireless networks.
Now, if congress could allocate the 500 to 600 MHZ range, for example, the problem would indeed be solved and it would be extremely feasible. One base-station could cover about 10+ miles.
However, all of these cable and wireless corporations would scream murder and pump billions into lobbying against such a proposal.