I am running out of ideas how to explain it.
So just listen to me singing :


As hashrate goes up, block rewards go down
But don't worry baby, don't frown
Cause we'll just find a few more blocks per day
I'll all average out for you, in a way

Dont spend all your time on slush' page hitting "stats"
The lower block reward will make you go nuts
Switch over to graphs, at least for a while
Day earnings quite constant, that will make you smile

Besides, thanks for asking, my post count is fine
I really have plenty of time while i mine
But diff will go up, i guess saturday
And thats what will take our earnings away