[DerpDerpDerp]

ZeniMax was working on VR technologies before Carmack began interacting with Oculus, and has a reasonable claim to the fruits of his work on that (being that it was an assigned R&D project).

Do you really think I should (for example) be allowed to develop a new plastic in an R&D position as part of my duties at a chemical company, and then simply give the research over to a competitor because it strikes my fancy?

If Carmack wanted to retain control over his IP, or not work under the (pretty reasonable) IP assignment clause, he should have not sold the company or not stayed working there.

The fact is ZeniMax has several good claims: Oculus used id IP to promote their product (games), used products of id's (under ZeniMax) research in to VR, and so on.