The description of Greece as a 'leech' country is one I reject out of hand. I while wanting Europeans, and others, to live in peace and to trade equitably with each other and a Eurosceptic (or worse). Many Europeans holiday and some live wholly or partly in Greece and probably find her membership of the EU and the Eurozone convenient. Greek workers undertake work that Britons, Germans and others find beneath them. This is true of Poles and others.
Turkey is and has been strategically important. It represents a not insignificant and growing market which I suppose might be attractive to those who wish to see the EU as a heavyweight bloc in terms of trade, etc. It is also a controversial and useful 'lever' for German speaking peoples who wanted to see their old ally Croatia granted accession to the EU in spite of other countries concerns over co-operation or a lack of co-operation over handing over war crimes suspects. This appears to be one part of Austria's brinkmanship re: Turkish admission; the other being a fear of admitting such a large Muslim country to the EU.
For some, although nothing new, Turkish behaviour towards it minorities including the Kurds and various Christian communities is a long running and unhappy matter, with Turkey clearly in denial over the genocide of the Armenians in 1915.