ISPs literally can't lose customers because of their monopoly, and if one of the three major ISPs starts loving with customers, there's no precedent keeping the others from doing the same. A good example of this is when comcast introduced a data limit, and in just a few months AT&T followed.
On top of this, most areas supply only Comcast, ATT, or Verizon internet. If there are other ISPs, it is likely a child of these big names. So there isn't really an escape from it. I'm in that forgeted category, woohoo..
