I feel like this debate only ever gets two sorts of representation, the people who think every migrant is a desperate refugee in need of rescue, and the "fortress Europe, it's an invasion" people. I don't think those extremes are very useful in addressing this issue. There's a serious shift to the right wing in Europe right now, especially Italy and Greece, who are on the front lines of this thing.
Because the existing framework favors migrants once they reach an EU country, the countries where the migrants first land are incentivized to intercept and return them at sea... or just ignore them and let them take their chances.