... think about it this way
instead of getting same reward for 10h you get half of it for 5h
My point is this - On say a 12 hour block, loyal miners will pay a lot for electricity.
A pool hopper comes in within the last hour and gets the same reward for a fraction of the electricity.
I do understand that we may find the block a little quicker but loyalty is not being rewarded here.
It may also have been a "pool hopper" who found the block for us. I not a big fan of slushes system sometimes, but slush still has the highest payout.