Is Turkey either European or democratic enough to fit in with the EU or is it a ploy to make the EU border Syria?

No, and it is becoming more despotic every day.

The current rounds of purges should have ended any discussion of EU membership for Turkey.

Turkey is neither geographically nor culturally "European". Historically, Turkey was always a bane to Europe: Keeping the Greeks in thrall and invading Romania and Hungary and even attacking as far as Vienna. Culturally it does not share either Europe's primary historical religion or its modern day values of democracy. It is an oppressive regime with regular military coups that is best characterised in the movie "Midnight Express". Human Rights are at nil in Turkey.
It is saturated with Islamist Extremists and Jihadists and would just love to have open borders with the EU which would then fall faster than you could blink. For one thing, the EU would have open borders running all the way to Syria. For another, the EU is saturated now with Syrian refugees among whom many terrorists are hiding. But, on someone's bright side, it would fulfill the old Ottoman dream of conquering Europe.