I think it's the opposite if you actually want to make a difference. Pressure works best when it's concentrated. Protesting every, or most, or many companies will be extremely difficult and likely make no difference. Targeting a single egregious offender and punishing them until they change will motivate other companies not to be the nail sticking out lest they face the hammer of public opinion.

Sadly, I think there's not enough public will to punish entities like the NBA or Blizzard for their servile behavior.