Re: It it to do with the selling price I bet
Indeed that wouldn't be fair, however when A, B & C each have a big (differently sized) pile of patents that the holder of the patents in question wanted to use, then the percentage is going to be different for each company anyway, having been hammered out by patent attorneys considering the relative worth of each patent in the respective owners warchest against the perceived worth of the patents being licensed.
It sounds like the original deal was struck when Ericsson was making phones - now that they don't, leverage has changed as there is no incentive to license any IP from A, B & C, let alone D. It would be interesting to see what happens when agreements with Nokia, Samsung, HTC and any other company making phones expire - although perhaps they were made with a longer timeframe in mind.
The big point is, we don't know who is being unreasonable. Apple could just be being arrogant in their stance, or Ericsson could be being greedy - those details will come out in court (if it doesn't get redacted for commercial sensitivity reasons), or will be hidden behind closed doors when they reach a settlement.