I don’t get this comment. Gnome is not trying to make a walled garden, and Microsoft has taken every chance they get at making walled gardens (Windows phone, windows 8 arm, various proprietary file formats and protocols), they just haven’t been very successful at it.
Patents expire after 20 years, yes, but patents aren’t copyrights. No current copyright expires in 20 years. They all expire 70 years after the death of the author (or 120 after creation in the case of corporate with for hire)