Debit or ATM cards are different. They pull money directly from your account and can exist independently of Visa and Mastercard. For example, some credit unions still issue ATM only debit cards that are not part of the Visa or Mastercard networks.
And in Europe, when people hear Mastercard or Visa, they just associate the name with refused payments at points of sale depending on the luck they had with the merchant, or the foreign country, etc.
I do agree that in this case, picking MC/VISA is not really important. When I changed banks a few years ago, it so happened that I switched from a Visa to a Mastercard. Nothing changed save for the logo on the card.
But that might be one reason why business ideas from the US do not always translate well to Europe, and vice versa.
Europeans use these dispute protections much less, so Visa/Mastercard are mostly seen as expensive pass-throughs.