“We use them and don’t contribute anything back.”
This is not, strictly speaking, true. The example projects saw contribution in terms of code, testing, documentation, and - most importantly - marketing and evangelism.
These projects are not things put up on GitHub as a convenience that people just happened to adopt: the companies in question spent great sums of money encouraging adoption, usually with developer evangelists on staff who’d preach the technical advantages and talk about benefits of the licensing to convince people to use them.
It’s naive at best to position that as simple “gift culture” and claim it’s biased to call it what it really is: a rug pull.
In the case of Redis the company promised explicitly it would always keep the license for Redis core: until it didn’t. That’s a rug pull, plain and simple.
Accepting code and other contributions, encouraging other FOSS projects to rely on a project and then relicensing? Rug pull.
Show me a project that was not aggressively marketed for adoption using open source as a selling point and I’ll agree that’s not a rug pull. If Acme Corp just happened to have a GitHub repo for something under a FOSS license and people organically found and adopted it, okay. I’m not aware of any such examples, though.