Face it, friends aren't your guardian angels. They're not there to help you no matter what, no matter the consequences or even to be there for you anytime you want.
Though the romantic view of friends is so delusive, friends are people like you. They're subject to their own moods. They've got their problems. They face difficulties. They have priorities they cannot ignore. And never forget, they chose to be your friend. They may choose otherwise, you need only to do something they cannot accept.
Think to yourself now. Why you don't have friends? Is it because you're always doing something contrary to their beliefs? Is it because you didn't listen to their counseling, when what they were doing with the best of their intentions, was giving real advice, deep from their hearts.
Oh, maybe when they were needing you most, be at work or with a personal issue, instead of being compassionate, you chose to simply ignore their feelings and needs and acted like a complete stranger.
I have few people I can call friends. Those are people I respect, those are people that respect me. They know who I am, they know who they are. They're not there anytime I want, they're not my guardian angels, they're my friends.