c1, there's no reason why a Turkish chef can't rustle up a decent Chinese/Indian/Mexican meal - I'm sure they have access to pretty much all of the ingredients. Bear in mind that what we're used to are westernised versions of these cuisines anyway - try visiting a "locals" restaurant in London's chinatown and you'll see that the menu is completely alien to us!
You have to accept that Turkey is a budget destination, and the restaurant trade is geared up accordingly. To my palate, the food in the vast majority of restaurants is "adequate" and no more. But if I'm paying 20-25 lire for a main course, what more can I expect. There are a couple of better establishments in Olu Deniz (and there may be in Calis, but I don't know them) where the menu is prepared with a little more imagination and they are significantly more expensive, but generally it's a case of cheap, cheerful and generally good value. That's what the punters want!
As far as takeaways go, when it's so cheap to eat in, why bother taking it home? Having said that, I would guess that any restaurant will put a full meal in a doggy-box if you ask.
PS: How about the doner kebap? They're pretty good!