Just keeping moving the goalposts bud - it seems you have a never-ending following of 'believers' who will continue to shoot for goal. Oh wait, but you knew that didn't you?
This is actually softened now. I think the initial idea was that we should look at the whole history since pool's inception, so 30 days makes a bit more sense.
But now he is saying "gross". It would be ok if you could point your own miner at the pool, but to take advantage of ZenPool you are forced to use their expensive (both in terms of the initial cost and maintenance cost) miners. So this is essentially a loophole now allowing them to charge up to 100% in maintenance fees and still claim it's most profitable.