Of course, the actual negotiations for channels are (almost) never made public, but it was published here and other DBS sites in years past was that YES wanted carriage in the lowest tier with RSNs - the same tier as SNY and MSG are put on. Due to the higher cost of YES, Dish wanted it on a higher tier, and also offerred to put the channel as an a-la-carte choice with all revenues going staight to YES. YES refused these counter offers, Dish refused to pay $2.20 or whatever YES wanted to add it to the other NY RSNs, and there you go.
I would agree that anyone who wanted the Yankees left Dish a long time ago. I'm just a bit suprised that Dish continues to write off the largest market in the country by not carrying the area's most popular sports team.