For all WC qualifiers, the home team controls the distribution rights. For whatever reason, ESPN won't pony up the money for the away games. They own the rights to every USA and Mexico home game, so even when we play at Mexico, it is still on ESPN. Other countries could also just decide not to award the rights to ESPN even if they are outbidding everyone else for the game.
beIN sports (who showed the game tonight) has basically stepped in to replace Fox Soccer Channel as it dies it's slow death. I believe FSC is turning into Fox Sports 1 or something in the near future. It was way better back in the day as Fox Sports World anyways.