Do most people who try to join a frat get rejected?

I already graduated, so it is too late. I am still bitter about what happened during my time at UCLA and how I couldn't get into any clubs or organizations. I rushed numerous different times when I was a student here and just got denied. The chapter officers all disliked me and told me to get out at the first rush event. It is so frustrating how there is so little logic or reason behind who they select and who they deny.