On the other hand, no one is perfect. If you try to find weakness in others, you always find plenty. Other people will find plenty of weakness in you, too.
Your ability to see the bright side of human beings and work with the bright side of human beings gives you the tools to be successful. Paying attention to the dark side will only depress you.
So to answer your question: your observation is probably right, but it is a wrong observation to make.
I'm sure that you can tell the difference.