You think "a simple ability" takes less time. I think making it simple actually takes even more time, especially when Coinbase has a history of indemnifying its customers even when it wasn't responsible for the loss (GDAX/ETH flash crash), which means that a bare-bones tool with a ton of CYA documentation isn't going to cut it for them.
You saw a "solid bloc of support." I saw a fracas of tweets, bitcoin.org posts, and /r/b* proselytizing on many sides (not just for/against BCH but also for/against the other BIPs, as well as other things unilaterally calling themselves "consensus" or "agreement"). I'm still not convinced anyone but ViaBTC is in it for real (https://www.coindesk.com/even-miners-hate-bitcoin-cash-might...).
You probably believe BCH is currently valued in the mid-$200s. I see a thin market controlled primarily by exchanges imposing extremely conservative deposit requirements (up to 20 confirmations) that happen to function nicely as supply controls as well, and while I can't predict the future, I doubt an unconstrained market would send the price upward at this point.
Remember, the point of BCH was to make day-to-day on-chain transactions a realistic, scalable proposition. We're not even close to that being a reality, even in contrived pizza-buying scenarios. I'm still concerned that this fork will make exasperated merchants nope their way out of cryptocurrencies entirely, especially when intermediaries like BitPay face the practical usability nightmare of BCH and BTC addresses being visually identical.
Bitcoin has its practical use cases that have been hard-won over nearly a decade. Ethereum's elevator pitch is ICOs. Both of them have clear reasons to exist. But Bitcoin Cash's pitch at this point is "like Bitcoin but without the network effects." I understand where it wants to go, but for now it's just a speculative vehicle, and I understand why Coinbase doesn't want to help enable that usage.
