Why do the good guys always have to win?

Why do the good guys have to win?

After watching killers elite, I was really hoping for the bad guy to win in the end. It is based on a true story so I really wonder if the good guys did win in the end. That is even if they were considerd the good guys.

Like in an earlier post I put down in July. I thought voldemort should have won in the end. But hey sometimes its great for the good guy to win.

You guys think the good guys should win or not?

Thanks!