Some municipalities have made it very onerous for Uber to do business - Austin, TX. comes to mind. Uber and Lyft both had decided to not do business there, though I think that has changed in recent weeks. The usual suspects are in play here - the taxi lobby is strong in many cities and the government officials fall in line.
I think enough citizens have to make a racket about demanding ride-sharing services for these cities to yield. For example, enough of us here in San Jose made a stink about letting Uber pick up at the airport for the city council to agree to it.
You want to see a confusing legal situation for Uber? Come here to Newark International Airport in New Jersey. The airport straddles the municipal boundary between the cities of Newark and Elizabeth, which is also the border between two different counties. I believe Uber is permitted to pick up and drop off passengers at Terminals B and C (located in Newark), but their legal status is still up in the air at Terminal A (located in Elizabeth).