I would think that employees at those companies would probably prefer if they weren't doing business with some of those people, but I think it is much more difficult in cases where there is just a good being purchased through retailers (there are intermediary steps).

With these kinds of contracts it feels much more akin to a partnership, so I think the feedback makes more sense. Its odd to me that we question why employees would want to have a say in how their company conducts business. Sure, its a choice for the company to make, but saying it is entitled for the employees to speak out just seems insane to me.