The true reason has been largely ignored by the Northern Europeans, who tend to dwell on its impact on their own societies and particular circumstances.
Greece has had the impossible task of of policing the border with Turkey in order to stop these poor unfortunates from crossing the River Evros, its Delta and to nearby islands. Although Frontex has done its best, the problem is so big, that it is still vastly under resourced.
Should the moaning and groaning EU members stop and think for a moment, they would easily see that all their complaints are the result of either US led wars in the Middle East or due to well orchestrated political agitation.
Either way Greece's problems are the result of war both in the Middle East and in the past the Balkans, which have targeted this peaceful Christian country - now blamed, along with the Italians - for the recent migration into the EU and the often mindless complaints of certain hapless voters.
It is clear that those directly involved in these recent conflicts did not budget in their war costs, for the problems surrounding political and economic migration into the EU and are also very reluctant to pay for their mistakes as well.
In the midst of a national economic catastrophe, Greece's fellow members have proved to be only casual supporters of Frontex, and have virtually ignored the huge cost of housing and managing these unfortunate migrants, who are all destined to travel to Northern Europe, at some point.
Perhaps the winging EU politicians might address the real problems for a change, and to lean on the Turks - who have contemptuously let many of these illegal immigrants into Greece in the first place - in order to create a clearer and fairer picture.