Because he sees the person behind the flaws. We all have something about us that isn't perfect. It sounds like he wants to comfort you. This is a guy I wouldn't toss aside. He thinks your special, and that's definitely worth something. Sometimes it takes another person's perspective to see what makes us special.

I wouldn't start dating right now as I think you're not ready. I think you need to determine whether or not you're trying to force something that isn't there because of your grandpa. I suggest therapy.