The OP is onviously using hyperbole, but there are certainly long term effects from encouraging people to spend beyond their means. For example, it makes people's financial position more precarious: if your income is mostly committed to monthly payments, you are in more danger of getting into trouble from a layoff, illness, etc. If a big portion of society is in this position (and they are) this is a concern.

I think people should be allowed to make their own choices, but I don't believe it's harmless to promote living beyond one's means.

Right. Afterpay, Affirm, Klarna, etc. are generally not used by well off and financially literate/prudent people. Just like gambling and lotteries. They are generally used by people that don’t need help screwing up their finances. While I do agree that people should be free to do what they want I think it should be presented with some realistic and frankly harsh warnings.

You sound like a BNPL marketer. The loan has late fees, the app is branded as a easy POS way to buy things with money you don't have. There is no credit check. You can sign up to a dozen of the services at once. It is credit, it has the same negative effects as credit.

BNPL is as bad for people as 20% apy credit cards are.

Right. They are giving out interest free loans to people out of the goodness of their heart. What a swell company. Wait what? They make more profit when people fuck up? Well I am shocked.

Being more charitable, I think it's marketed as a way for people who budget monthly to spread their charges.

The point is that if they're stretching payments over multiple weeks/months then they can't afford it.

Would you say the same about a house? A car?

You might say that buying a house on credit isn't frivolous but a pair of shoes on credit is, but where do you draw the line in the middle?

(Disclaimer: I work at Square, but I am otherwise completely uninvolved with this acquisition or product area.)

What is your logic behind that?

the business model is that BNPL will eat the risk, they won't sent a debt colector after you, they simply won't loan you more money. It's much more humane than credit score which is a form of social credit.