The author (who seems to use his cards in Germany) is most likely confused. The problem is not with debit cards vs. credit cards. Every terminal I've seen in Austria and Germany supports both (but see below). The problem is that Austrians, Germans, and perhaps other EU countries think that Mastercard/Visa means credit card, and Maestro/Giro/whatever means debit card. This is exacerbated by the fact that until very recently you couldn't even get a Mastercard/Visa debit card in Austria (1).

These terminals support Mastercard/Visa cards, plus more recently contactless. Mastercard debit cards certainly work.

Btw, if you are an american visiting these countries, and you want to pay with a debit card, when the cashier asks if you pay with a debit or a credit card, answer credit card. They don't care whether it's credit vs. debit, they need to know if it's Mastercard/Visa or the local crap card, to push the correct button on the PoS. If you answer debit, it will NOT work.

1. Austria recently started replacing Maestro cards with Mastercard debit cards... but they seem to be some kind of funny Mastercard cards, not "real" enough for these terminals (except in contactless mode)... But at least you can pay for your plane ticket.