If you looked at the top 5 Google results across all key words and men wrote more of the posts than women, would you accuse Google of bias? Or would you consider that maybe its evidence there are more men writing on the web than women. I don't see a difference here. Gabe's said that his system adds new sources programmatically as they get linked to. Why on earth would he block out female voices?
It depends on how much more. Women write roughly as much as men in the blogosphere, so if the overall results were (say) 75% male it would indicate a bias. The times I've looked at Techmeme and memeorandum they're usually 80-90% male.
I don't know why Gabe blocks out female voices but from the Atlantic article linked to in my thread he doesn't seem to read any women regularly so my guess is that he either (a) doesn't know he's doing it or (b) doesn't care.