I am sure they gain something from it.

My Brazillian bank charges me 600% yearly interest on credit card purchases.

However, the cost of a lawsuit can quickly offset the costs of a CC. Depending on the state, there may not be a maximum cap on expenses, making lawsuits incredibly expensive. (Whereas having paid by card you could ask for a chargeback instead of needing to sue)

It's also a very time consuming ordeal having to sue vendors in these instances.