Yes, of course they have complained to the courts. That's not the point. This simply will go nowhere, or do you expect that the court will somehow separate Activision out of Microsofts hands again to fix this? Or punish the managers at Microsoft and make them withdraw the execution plan to remove redundant jobs?
At the end of it, Microsoft will eventually pay a small, symbolic sum which they consider "cost of conducting business". Nothing more.
First of all, consider how many hours of use you usually get out of such a AAA title, and you will see that it's actually quite cheap entertainment. And second, there are good games (to waste countless hours on) that are way cheaper.