True. Optimum mining profit states that BTC/BCC hash power and price will have the same ratio. However, there are two important factors:

• User adoption: I think that majority of users prefer hodling BTC than BCC. Big amounts of BCC are trapped on Coinbase, other exchanges and wallet that does not automatically split coins. If my statement is true, as more and more BCC is split, more and more BCC will be sold and BCC price will drop.

-New York Agreement: Signers of this agreement control more than 80% of Bitcoin hash rate. As long as this agreement remains active, a vast majority of hash rate will be supporting Bitcoin. However this agreement is quite fragile. Bitmain, one of the members with highest hash rate, already said that they may start mining Bitcoin Cash if any of the members do it before.