Look at the number of MIT projects with such founding and contributions. Compare them to copy left projects.
What you will find is, that copy left projects have far more backing, financial support and contributions.
There are studies on this...
Qnd to keep Microsoft as an example. If the kernel would be permissive, what would Microsoft stop from using it, adding some property stuff on it and use their monopoly to force those feature everywhere.
Now they have taken the work of thousands of contributors and take all the money.