If they wanted to be compensated they shouldn’t have released it as “free” software.
Ge do you own the copyrights to the code from BusyBox? No? well then you dont get to tell the people who *do* own those copy rights what software license they can use. I know you believe you should be able to exercises quasi dictatorial powers to make sure everyone used a licenses which either:
(A) Locks the code down so nobody can see it, alter it
or
(B) Allows businesses to take the code and never contribute back to the project
But in the real world Freedom means people might licenses their software under terms *you* don't like. That does not mean you should endorse their copyrights be violated.
Anyone can cry about freedom and liberty when people are doing something they agree with but only people who really believe in freedom would protect those who are doing something you disagree with..
Releasing it under the GPL allows them to be compensated by the additional contributions made by other. Just because the transaction doesn't involve cash doesn't mean there isn't an exchange of value.
The irony of the GPL is that, much to Stallman's chagrin, it actually reinforces the ideas of intellectual property ownership and fair compensation for the use of other people's work.