In China they don't have subs. In China they pay by the hour in game palors (like buying hot spot wireless time).
Besides, US players (and EU players for that matter) don't play with them.
What counts for each region is who plays with who, as MMOs need the numbers to be even operate (groups/raids can't occur without enough players).
Subs sink in the US (or the EU) enough, game play becomes affected.