"Pawns are where our future members come from. We should encourage brain pawns to play all they want."

I agree, it is simple. Not enough money is ocming in because not enough people are becoming paying members. Supply and demand can be used here. The demand for a membership is too low. This might be due to excess supply. By reducing supply (reducing the benefits extended to brain Pawns), demand will increase, because a membership will be worth more. Right now, it does not appear that a mambership is worth enough for people to become members.

I would guess that the thought process goes something like this: "Hmm. If I become a member, I can join fellowships and play unlimited games. But I can play 20 games for free, and I don't really care about joining fellowships. so I'll continue to be a brain Pawn."