Because every time someone checks it, it turns out it's not implemented in a secure way. You really don't want an accidental transcript of your PII and payment

Because every time someone checks it, it turns out it's not implemented in a secure way. You really don't want an accidental transcript of your PII and payment details to just stay there, readable to anyone with access to your user. And that's even without being sceptical and expecting the information to be mined and sold soon.