Internet isn't free, you are still paying for the service. The question here is that they wan't to charge more for different sites than others, meaning that those sites that has a profitble goal, like netflix, get a unequal fotting when it comes to compettion, wich is the basics of a stable economics. Compettion > monopoly...
Why they aren't improving it? Because it's their way of regulating a sort of "supply and demand", if they upgrade it, they have to charge less for the internet, because it can handle more traffic, does lowering the "supply(connection speed)" and with the amount of demand, they can charge a high price. Take New York for example, one of the biggest stock-marketing metroplitan in the world, would benefit sooo much if they got better internet, but the fact is, that there is little to none to even upgrade the net to fiber-optics.