My wife complains to customer service without any expectation that something will change. If she gets a refund or partial refund, she's somewhat more mollified, but she will definitely write a complaint even if she has no expectation that there is anything that can now be done about her experience. She mostly wants to vent, and for the company to validate that they screwed up and seem apologetic about it.

Contacting customer support doesn't make me feel better, and it's almost always more bother than any refund I could get, so I don't do it much. The article is indeed about trying to get something fixed, but I wouldn't call that a complaint. It's more a suggestion.