I work making games, I never figured the point of using unit tests.
Also yes, multiple inheritance and that shit is pure evil... Once I tried to make a game engine using very strict OOP. It took me two years to make a barely working game... It is great to impress employers, but I don`t plan in ever writing code like that again.
But I won`t say this is not only good thought. I feel many times that I should know more, even if is to know why I am not using it.