They already know about it.

Hive account@dan has stated that the purpose of the liquidity reward is in part to subsidize liquidity but also in part to serve as a component of the distribution strategy for Steem. By offering such a bounty it brings traders to Steem, an audience which would not normally be interested in the social media aspect (though they may indeed post about or discuss trading).

Some tweaks are planned to improve the algorithm, but in a sense traders being clever and figuring out how to collect it is the whole idea. The same applies to saturday/sunday who appears to be trying to compete along with others who will join the game later.