There doesn't seem to be a joined up approach to border controls in the EU, individual countries seem to implement their own strategies to appease their citizens. The eastern bloc, Hungary for example, steadfastly refused to take migrants from the outset. So it's to a handful of countries migrants tend to go. When certain areas perceive they are taking disproportionate numbers feeling they are swamped it's bound to cause discontent. I remember a while back, Italy felt they were floundering with such a problem when migrants tried to cross the border their border with France who wouldn't accept them, like us Italy were annoyed with their neighbour. It does seem a case of individual countries implementing their own border controls to stem the flow more than ever lately.