There's absolutely no reason I can think of for doing that - instead of posting a price if USD or EUR and accepting paying in TRY. They'd have to exchange that

There's absolutely no reason I can think of for doing that - instead of posting a price if USD or EUR and accepting paying in TRY. They'd have to exchange that Bitcoin for TRY anyway to pay their local staff, and they'd have to convert the balance to USD or EUR anyways. It's just extra lossy steps with huge volatility.