It's a complicated issue. Banks are partly afraid of adopting something new. If Bank A is amongst the first American banks to switch and something goes wrong, Bank B may win its business due to customer frustration
I highly doubt that banks really care about "customer frustration." If they did, then they would be focused on fixing a million different existing problems.
Given that, despite all the customer frustration that exists right now, they haven't been losing customers. I don't think that Chip+PIN failing to work correctly at first would cause customers to switch. Chip+PIN cards would only be cycled into use gradually, as people replaced their older, swipe-only cards with Chip+PIN cards, or signed up for new accounts. There would be more than enough time to sort out any problems, and you could also start out by making Chip+PIN optional for new/replaced cards.
