I understand Banks take a long time to transfer the money back and forth but look at something like paypal for example, its instant. its purposely done to force its user base to give up personal information for ease of use.
ever received an eCheck on paypal? It takes days to clear. The bottleneck is the bank, not the exchange.
In fact, the ONLY reason paypal offers instant transactions is because they know who you are. So, how does that make Coinbase any different?