Can Polish citizens fly via Turkey just with a national ID (without a visa or passport)? Entry in the destination country is possible I'm sure, but the flight has a transfer in Istanbul Airport.
Polish citizens are not allowed to enter Turkey with their national ID’s.
- The Netherlands
- Turkish Republic of Northern Cyprus
If the trip is in one booking, you do not need to enter Turkey, and therefore don't need a passport.
However, awareness of this fact varies greatly between airport ground staff - anyone not understanding the fact that transit normally doesn't require anything but a connecting ticket (this ignorance is depressingly common) will deny you boarding.
So to be safe, bring your passport, but an e-Visa is definitely not needed if the trip is in one booking.