Right, but when companies go after pirated games, they are going after them because of copyright, not patents or trademarks. The way copyrights are enforced and the way the law works is a lot different than how it works with patents and trademarks.

There is no "use it or lose it" clause for copyrights. If somebody is breaking copyright, you still have the right to enforce it for a long as the copyright is still valid, and don't have to vigorously defend it to keep it.