Suppose Intel would have released its modifications and enhancements to Minix, for all to use, including its competitors. It's really difficult to think that Intel would be any worse off for doing so than they are now. I don't think they got any competitive advantage for using the MIT license.
I also wonder how effective it was at actually preventing the work done by Intel to benefit their competitors. How many Intel engineers were obliged to seek employment with one of Intel's competitors?
With all of the layoffs happening, I think a lot of companies are going to come to regret all of their intellectual capital which the engineers take with them between their ears when they leave.
The biggest advantage of the MIT license is also its biggest disadvantage: you do not have to give as freely as you receive. Everybody can have a proprietary advantage. Or, put a different way, somebody can take your work, and give you nothing in return, no money, no recognition, nothing.
It is useless to complain about somebody using your product in the manner you licensed it.