Re: [400GH/s] p2pool: Decentralized, DoS-resistant, Hop-Proof pool
They don't waste resource, a share is only rejected if it both arrives too late and doesn't solve a block so there's no,zero,0 income wasted by these rejects. I repeat: rejects don't reduce the pool's income.
most ppls are being scared of because they think their rejects are wasted work, donst matter how often u say it, dosnt help 
we would need somewhat like a FAQ explaining it maybe.