Apple presently has the most to lose due to the size of their bank account. I think when they were forced to settle with Nokia they realized you must play the game to win. The companies that have decided not to play to win are being naive in my opinion.
If Apple ever ends up in a situation where iOS is the only mobile smartphone OS left, USDOJ antitrust will probably obliterate them. No more facebook integration, no more app store, no more curtailing customer choice, and all of the other shenanigans Apple does under the curtain of "freedom of choice".
Not to mention that there are plenty of tech giants out there who have not been whalin' on every competitor that moves with their tech patents.
Some companies seem to be staying true to the "defensive only" patent policy, Apple is one of the few that are weaponizing theirs to large degree.