If you are distributing GPL'ed software you agree to abide by the GPL. VMware violates this by not distributing the source code for their changes. VMware is not forced to use GPL'ed software, they have chosen to do so by their own free will. They could have built their own software instead - which would most likely have been so expensive that the company would not exist. The honorably thing would be to distribute their changes thereby giving back to the ecosystem that has helped the company; GPL simply makes it a requirement to do so to their customers.
If you want the free software ecosystem to flourish please support Hellwig's case: https://sfconservancy.org/linux-compliance/vmware-lawsuit-appeal.html /Ole
