The program is even only partially free. The server part is proprietary, and
the assets are as well.
Now, let's see:
Semifree client used to connect to a proprietary server to download
proprietary games. Sadly, that's how some 'open source' software is. Free
software isn't like that, though.
The only reason Desura was released as 'open source' was probably just to
attract attention. Companies do this all the time. It's wrong, and yes, I
agree that it has no relevance to Trisquel, because it doesn't.