You are correct, a car that is beat on is a car that is beat one. Synthetic oils can reduce the damage that is done though.

There is a difference between a mechanic and an oil speciallist. Just because he can change parts on your car, doesn't mean he is an expert on oil.

Not everyone needs synthetic oil, sometimes dino is more than enough, sometimes a synthetic blend is enough. There are plenty of situations where synthetic oil is worth the added cost, even on small, daily driven engines like B18's.