(For those not aware, Bitcoin Cash is a fork of Bitcoin that removes segwit, the initial groundwork for off-chain scaling solutions, and instead simply increased the blocksize; so far this has proven to greatly reduce network congestion.)
Maybe it was the right call for Coinbase to not support many of the forks, but they will be adding support for Bitcoin Cash in 2018 (at least withdrawals). So it’s inaccurate to characterize Brian Armstrong on the “losing” side of these debates.