You think they don't know that? It's not about economic pressure. It is about political pressure. The boycott gets a headline and you repeat it in your denunciation of the boycott. It's a win-win for political pressure as even opponents draw attention to the position DPS has taken.
As far as China and Mexico... Their laws do not impact us the same way that the law of another state do. It is quite obvious that people are more concerned about the shit that hits the fan than they are about the shit that does not. Look at asshat and the AA whiners. They only care about the shit that hits on the very center of the fan.