Funny I never use the front-page and visit sub individually. I had never considered that I may be abnormal in this regard. Damn now I want to see metrics on this...
My gut tells me that part of the reason why Reddit was a flop is AdBlock. I would not be surprises is much of r/programming ran it. These guys are tech savy without necessarily being in the start-up scene.
Numbers that low could be attributed to miss-clicks, users who thought it was an r/programming post.