Anonymity is very important.

Here's a example why, that recently happened to a workmate:

He applied for a mortgage to buy a house. The application was denied 3 times, despite his having been employed at the same place for 20 years, paid all his bills on time and never received so much as a parking ticket. Finally, after insisting heavily and threatening to sue, his bank provided the reason why: his purchasing habits included too much alcohol.

Or said another way: the bank watched what he purchased when doing his groceries for years and quietly classified him as a wino and potential deadbeat.

I can tell you, when I do my groceries, and back when I still smoked, I never paid for alcohol or tobacco with anything other than cash, for that very reason. The only things I pay for with plastic paint the portrait of a boring working stiff with no habits out of the ordinary. For the rest, it's cash-only.

And if you want another example of why anonymity is important: a few years ago, I sought the help of an underground surgeon to perform a certain type of surgery on me that my stupid doctors here refused to perform, despite my quality of life going to shit (it's a long story...)

Guess what: underground surgeons don't take credit cards. The man changed my life for the better but I certainly don't want my local health insurance to know about it. Was it illegal? Hell yes. Was it justified? Hell yes. Legal and right are two different things.

And similarly, I expected many women post Roe v. Wade would like to have the opportunity to get an abortion out of state anonymously without going to jail.

That's why anonymous payments are essential: they are the last rampart between you and unjust laws and prejudice.