Visas are the permission a government gives to non-citizens to enter their borders. This competency has been given to the EU to manage as part of the Schengen Area, which is a visa-free zone for all EU citizens.
How is a group of towns going to start restricting access to their communities without seeing up a border?
And why would a German doesn’t need a visa to visit Spain, why would a hotel ask for something they don’t have?