I agree with Matty: I think people are just generally not forgiving enough.
Unconditional love is a myth. It is unrealistic to expect it. Everyone has a line, once that line is crossed....
I find that I am much happier in my life by being forgiving of others. I don't intentionally hurt the people I love, but I'm sure I have at one time or another. I only hope they are compassionate enough to forgive me and give me the opportunity to make it up to them.