I don't see how that is illegal because the cards WILL eventually go to EU (dealing with VAT up front is less hassle for both parties in my opinion). Unless there is an agreement to ensure that cards will stay in the US, only then charging VAT for EU MIGHT be illegal. I don't work for ALLMINE; just my personal view on the whole VAT thing.
You don't see because you don't know.
https://ec.europa.eu/taxation_customs/business/vat/eu-vat-rules-topic/chargeable-event-chargeability_en#_Imported_goods"Importation of goods from outside the EU
Basic rule
The chargeable event occurs and
VAT becomes chargeable
when the following types of
goods enter the EU"
goods that are not for free circulation in the EU