Use this information to your advantage, that way you can spot your biases.
Furthermore, you could know a lot about the person in front of you by observing that.
While it might be true, often times it's someone who took advantage of other people's trust and betrayed others.
Others who claim that humans are inherently bad, are bad people themselves.
A good person sees the good in others (A smart one is also aware of the evil part, but that's another story)
Just be careful, this indicator could spare you a lot of pain.