Because you make a mistake and believe humans are a benevolant species...and you want to believe that...no matter what.
The fact is, humans are an evil species. Of course there are exceptions, but by and large...the vast majority of humans are evil, warlike creatures, with a propensity for deception, trickery...misery
Not much has changed in the last million or so years.
I don't agree with your cynical view of mankind.