I think they're beginning to realize that "word has gotten out on the Internet" that "squeaky wheels get the grease" so they are curtailing the extent to which they do lower cable bills on request, as they have in the past. Previously they did so because a good number of the folks calling in actually would have switched away if their bills were not lowered. Now they know that a good number of folks calling in are just trying to "work the system". (It should be noted that I did just recently get one of these $40 reductions, good for six months -- but perhaps they keep track of how many times you ask for that reduction, and after once or twice, they stop granting it.)
Beyond that, I think it is becoming clearer that the grass isn't always greener on the other side. I have records of an eighteen month campaign of mine to get FiOS to provide service to my part of the street, after they ran the fiber past our home in summer of 2007. Once I was finally successful, I started getting inundated with offers to switch to FiOS -- which was great as far as I was concerned. Then, I started gathering the information about how much it would cost me to replicate the service I had with Comcast. FiOS wanted a lot more money (mostly because of how many televisions I have cable service on). I also started gathering information about what I have to do to reconfigure multi-destination port-forwarding, and CableCARD pairing, etc. It was pretty significant -- I would have to learn about router bridging, and a whole bunch of new things that I didn't have to know with Comcast.
So all this great promise of competition was really just propaganda anti-cable people fabricated. Competition comes to town, and effectively they want more money, not less, and they make things more complicated, not simpler. In our town we have Comcast, RCN, FiOS, Dish Network and DirecTV, and the legacy cable company, Comcast, is still the very best option, given all the parameters, for many people.
I understand your desire to get that great price break, but I think what you're encountering is this fiction you've been sold in the past finally hitting the brick wall of reality.