They are perfectly entitled to stop ‘planes landing at their airports. Here’s a list of Airlines that are currently barred from landing in the EU:
Iran Aseman Airlines (Iran)
Iraqi Airways (Iraq)
Blue Wing Airlines (Suriname)
Med-View Airlines (Nigeria)
Mustique Airways (St Vincent and the Grenadines)
Aviation Company Urga (Ukraine)
Air Zimbabwe (Zimbabwe)
Avior Airlines (Venezuela)