Ontopic: All open source games suck. I have played many of them and they are all horrible. I suspect that this is only "news" because of the game's license and not because the game is even remotely good.
As an open source game programmer, I take offense to this. Heavy offense. As an open source gamer, I disagree. Open source games are great because if you find a problem, you can dig and and fix it. You're free to improve them.
Contrast this with, for example, Marvel: Ultimate Alliance. I love the concept, I love the gameplay, but what I don't love is the huge number of typos in the dialog. I can't do a thing about it. On the other hand, I was able to do a complete overhaul of the dialog in FreedroidRPG, and I'm now a member of the dev team.
As far as your experience with open source games, I doubt you've played a significant portion of them, and I highly doubt you've kept up with the updates. Yes, updates, new developments that get pushed out for public consumption. You don't get that with many proprietary games. You might get 3 patches, and that's it. No new content, just bugfixes. *That* sucks.