The point is that refusing to trade with someone because they said something you don't like is not a good way to make money, and as such, one way or another, companies wouldn't take such measures were it not for the government's influence, regardless of the precise means of operation of that influence. If it were like you say, we'd see the influence of the companies undoing such government policies so that they can be unrestricted in their trade and make more money. That's not what we see. (Or likely we see it in other areas, but it's clear which way the influence runs in this one.)