This is an unfair slur. I've visited many pre-Moslem sites in Turkey, both Hellenic and Byzantine, and they are well-cared for. Worth a lot in tourist $$$ too.
unfair slur??? You must be joking.
In fact, less than 5% ---and probably less -- of the pre muslim sites are preserved. In the interior the "museums" are a joke and most of the pre islamic heritage (churches, monasteries, towns, whole ancient communities for God's sake! - have been destroyed, stolen, sold, much of the art/Christian iconography-objects d'art-- resides abroad who knows where.
This is true of much of the muslim world.