I don't agree that shopping elsewhere is the only complaining that works. When you publicly complain about a corporate policy, you can raise awareness in others

I don't agree that shopping elsewhere is the only complaining that works. When you publicly complain about a corporate policy, you can raise awareness in others and build a consensus. If enough people agree with you, the company may feel compelled to change course, or sometimes even legislation is enacted. Or a competitor will notice the swell of unmet demand and step in with a better product. But if all you do is keep to yourself and stop buying, then your protest begins and ends with you. So, certainly not always, but at least sometimes griping and grousing works.