This kind of over-dramatisation is totally unwarranted. Unlike slavery, participating in open source is completely voluntary. Unlike colonization, no one is taking your ancestral lands from you. Unlike most kinds of exploitation, the “exploited” can end it any time they want to. No one forces them to continue working on their open source project.
I fully agree that more people should donate to support open source, but this is not a violent or coercive situation.
Money is not the only motivator in the world. Most open source maintainers are (evidently) not doing it for money, but are motivated by altruism, passion, recognition, etc.