I don't think it's saying to stop using the Internet, just that if you're talking to someone preaching to avoid Amazon retail purchases to avoid giving them money with the goal of bringing down the company, pointing out the fact that only avoiding retail but still using websites that are hosted on AWS is hypocritical. It's hypocritical because they will then start making excuses about why they won't stop using those websites, which shows that they only care about "fighting" the evil of capitalism when it's convenient (or only mildly inconvenient) for them.

Using some certain technology or service doesn't mean we agree with their leadership or policies

Absolutely.
Especially in a world they've manufactured specifically to leave us no choice, from food, and hygiene (and cosmetics, which like fashion are entirely manufactured for profit and perpetuated by the media.) to energy, and so on and so on.
Wherever we spend, it almost certainly ends up in the hands of one of a few hundred people, that have created an illusion of choice.