Why to take the burden of these wallets and private keys when exchanges give you the offer to have both the coins. Yeah you read it right. Most of the traders would know this that bittrex is offering 1:1 ratio of bitcoin and citcoin cash after the fork. If we have 1 bitcoin , we will be having 1 bcc and 1btc after the fork. I have deposited all my coins on bittrex and there is no burden to me now. I can trade whenever i want, sell off my bcc as soon as i get it. Most people will sell bcc after the fork and that will surely make the price of bcc go down. Having bcc on exchange will give you an advantage to sell it before others.