Companies don't normally fail because of security flaws, in the same way Boeing doesn't go bust when it has to ground 787s. But in both cases you end up potentially taking a huge hit in costs. Off the top of my head, Sony had to write down $170 million in costs when PSN was compromised, and TJ Maxx ended up paying out $800 million in costs, damages, and compensation after their payment terminals leaked credit card details.

These are not figures you want to see on your bottom line.

If your first reaction when someone talks about security flaws in payments is 'will it make my business fail' rather than 'is this going to fuck my customers' you need to re-evaluate your priorities.