I doubt they pay more for their use of H.264 than they receive from everyone's use of H.264. Providing the codec may cost them money, but it's far from obvious that it's an unprofitable act.
I guess that, for most of the companies on that list, it is a 'pay a bit to prevent legal troubles' scenario, where 'a bit' is a couple of millions. Some of that they will get back when MPEG-LA gets disbanded.
