That's simply not true.... the merchant needs a contract to also process (foreign) credit cards but the POS machines are identical. And almost all ATM's accept international cards from Visa/Master.

What is unique is the debit cards that are used in the Netherlands, but that's not relevant if you are a tourist. It's just that some places only accept debit cards because transaction fees are so much lower than credit card payments, and 99+% of the population has one. There cash is the only alternative as a tourist.

Edit: saw your reply after posting: Yes, cash is the option there. The smaller merchant simply are not interested in paying 2,5% (with a minimum fee) for processing credit cards. They aren't very interested in that when I pay with a European card either. And Amex is even worse with 4+%.