I see many times chefs choosing olive oil as the fat for cooking recipes that undergo heats of 400f+ (very much above the smoking point of refined olive oil) for 30 minutes, and its virgin olive oil many of the times! But isn't olive oil supposed to smoke at those temperatures? Does cooking past the smoke point not cause smoking and undesirable flavors or other issues? Does any flavor benefit from the oil actually remain?
Just because the oven is reaching high heat does not mean the olive oil that is on the surface of what is being cooked will reach the oven temperature (or get past the smoke point, even). In a deep fryer, heat is transferred almost directly from the heating element to the oil. In a pan, heat is transferred from the heat source to a pan, then directly to the oil. Both those represent very efficient heat transfers, and can bring an oil to past its smoke point. The oven transfers heat from source to food via the air, which is a very inefficient form of heat transfer. The temperature of the oil you apply to your food will be vastly more affected by the mass of the food than by the air in the oven environment.
Smoke is not inherently a bad thing - look at the popularity of barbecue preparations, or the wide variety of both traditional and modern smoked foods. Why wouldn't a little bit of that flavor enhance whatever is being roasted?
Olive oil itself also has a robust flavor, and it browns nicely. So in many ways it contributes to the flavor of the finished dish. An oil isn't suddenly ruined and inedible once it hits its smoke point - it just starts to smoke.