Why do some people not talk or not like each other?

Why do some people not talk or not like each other?

My last 5 years ,I focused about this question. I talked to almost 500 people.
The most answer were:
1-Because He/she did something bad to me.
2 -Because I heard He/She is not a good person.

My second question was:
Did you talk to a person face to face? The most answer were:
1-No, I don’t talk to Him/Her. I am done.
2-Yes, but we fought again.

So far my view about this result is:
1 -Everyone has their own values and judgment about another.
2-Lack of tolerance and patience

No one in this world is perfect,So judge less and love more.