I think you're saying that you don't believe in the freedoms to use the GPL licensed test suite for certain purposes which are explicitly allowed by the GPL.
You don't get to choose a license and then add extra terms to it when you don't feel like it's up to scratch. That's something explicitly not allowed by the GPL license.
Where does the GPL say you have the freedom to relicense code or derivatives under MIT by fiat?
Isn’t having to stay under the GPL a very big part of the GPL license?