Agree, people will sell immediately if they get free money from bitcoin branch which named bitcoin cash or maybe they should named it 'bitcoin crash currency'. But I doubt more exchanges will list this coin if they feel it maybe inflict a financial loss, and so far just viabtc announced support BCC. Digital currency price will be determined by its usability, none of altcoins could compare or compete with bitcoin, altcoins will always become trading object including BCC.