The political tradeoff comes from the franchise agreement. Your citizens want cable tv, and Comcast only wants to wire up the higher-end neighborhoods because they'll buy more services. Is that how you want to be portrayed? So you tell Comcast to make the deal: wire up the whole town, even that neighborhood 3000 feet up the hill, and we'll guarantee that nobody else can interfere with your physical plant investment. Comcast sleeps soundly at night, and so do the politicians.