Right, but that doesn't imply malicious intent and it doesn't disqualify them from building their own. Talking to companies about their product and then later

Right, but that doesn't imply malicious intent and it doesn't disqualify them from building their own. Talking to companies about their product and then later deciding you'd rather build your own isn't really surprising. Plaid was definitely aware that Stripe was a potential competitor going into those meetings.