The fork did occur but many miners abandoned BCash coin right after it split from the main chain. The exit of the miners results to extremely delayed block creation due to the pre-calcuated difficulty and as a result no transactions with BCash can go through. Overall it fails as a currency, but does decently well on exchanges in spite of the inability to deposit.
Once the difficulty goes down more miners would go back if there is a profit incentive.
Nobody can really say it is failed until a few months from now. There is still a chance it will succeed as an alt coin.
If the difficulty drops by 20 times and bcc is worth 1/5th of btc, then miners will to to bcc. They will just switch between coins imo