They failed to realise the seriousness of the situation. Reason why the EU is now trying to bribe Turkey into stopping the flow of refugees.
More will come, with the Russians bombing the rebels and the Syrian army advancing on Aleppo more will flee the city. Another million possibly, so the situation will worsen. More refugees just stokes anti-muslim rhetoric in Europe. There is no solution, the handling of the Syrian war and the refugee crisis is a great example of clumsy diplomacy and bad leadership from everyone involved.
I mean the Kurds the Germans and Americans armed to fight ISIS also just happened to flatten Arab and Turkmen villages in Northern Syria, literally wiping them off the map so they could land grab which is a war crime as Amnesty International reported. Nobody knows what they are doing.