The white paper states Steemit has deliberately made the rewards for earliest votes highest, in order to reward those that discover content and curate it first more, to encourage curation work.
I fail to see that accounts randomly accessing Steemit per schedules that have nothing to do with when posts are made could possibly be advantaged by this. However, self votes, and coordinated cliques, certainly can.
Draw your own conclusions as to the true motivations behind this mechanism.
Edit: speelingh. Hookt ahn fonix rilly werkt fer mee!