Debit cards can be given to an underage, so I suppose they don't accept it for this reason.
In the US you're usually inundated with offers to open a credit card (often pre-approved) right in your mailbox. Even if you're a poor recent immigrant, or something.
I feel in Europe having a credit card means the complete opposite, only "rich" people have credit cards.
I have a credit card, I use it, I pay it off every month. Why am I seen as poor just because I have a credit card? It's just a tool. It spares me from needing to maintain a 10000$ emergency fund in my checking account.
* Passport
* Identity Card
* Driver's License
It rejected my Driver's License and I gave up after that.