That goes, however, extremely strongly against the social contract between Moscow and Russians.
If they start doing that, then there's a very serious risk of rebellion in the Russia. They might go for forced conscription, but especially if 80 % of the conscripts die more or less immediately, Putin's head can very soon say "bye bye" to Putin's neck. That will be the end.
Once you go for sending all 18-years to die in Ukraine, things will explode in such a magnificent manner that just retreating from all of Ukraine will cause less backlash than that.
The point of a directive is that it outlines what kind of law should be written in each member state, but each member state has a lot of leeway regarding how they decide to implement the directive.
Then there are another category of EU laws: Regulations. Regulations must be precisely the same in each member state.
But, if what you say is true and it's indeed in a directive instead of a regulation, then the reason is simply that Germany decided to implement the directive in a way that doesn't require ATMs to give receipts.
A directive defines the rough outlines of a law, a regulation is a ready-to-use law that cannot be altered in any manner whatsoever and is automatically valid without parliamentary interference by the member states.