Well most people do have easy access to BTC. If they don't I doubt they would get into mining, let alone into mining ETH.

My point stands that people are better off just buying ETH right now from an exchange like Poloniex, then buying mining power with Genesis-mining. I think Genesis-mining should pass on more of their saving to their customers. They are keeping so much for themselves that their proposal just doesn't make sense for a customer anymore.