If Fark wanted to link to you, but required a link back, would you say no?
If you and me both wrote news blogs, but I covered Right wing news, and you covered opposing left wing news, and we agreed to trade links to expose our audience to each other's views - would that be a bad trade? I think it would be fine.
You're linking to something that's relevant and getting a link back from a relevant source as well. It's better than no links.