What dump? Nobody bought any in the first place.
You don't have to buy it to obtain it.
Anyway, I suppose that the >$100,000,000 of volume per day was people selling it to themselves? No one bought?
That is not the reason why people are finding it difficult to sell. Bittrex, Kraken and Bitfinex are all handling Bitcoin Cash.
I would say it's a mix of demand for Bitcoin Cash and concerns about the security of exporting people's private keys to the wallets which support Bitcoin Cash (Electron Cash in particular, as people don't bother to run a full node).
It would be dumb to pretend that the demand doesn't exist, because it does. However, there's no need to have FUD, because the market is showing what it regards BCH to be worth. Currently, it regards it to be worth about 0.1 BTC, which is not a lot at all, nor does it matter.