According to this system then, your ability ranks less than your available free time. 50 players who play 1000 games each but poorly get all the top spots, while the skilled players who play 300 games each lose out.
For a logic puzzle site, that doesn't seem very logical.
I understand the dilemma, but I think a fixed cutoff based not on points but on number of games would be a better reflection. For example, rank only those who play 100 times per month or more. This removes the ones who play only a few times, but still rewards the more skilled over the more prolific.