They blame Catholic schools because its an easy way out and they will take no responsibility for the problems themselves mate. I was raised a protestant and went to a mixed school, my father was ex orange and a mason, all of my family were huns and I was taught by them from a young age that there was a big difference between us and Catholics, dont trust Catholics, keep away from Catholics, Catholics are dirty, you fucking name it I heard it as a child. I never heard any of that shite at school it was all from home.
Anyway as I got older in my early teens more and more of my friends were Catholic, to me they were decent people and not immersed in bigotry like "my people" this trend continued until now. I can honestly say I have never experienced bigotry directed to me from a Catholic and when I jumped the dyke completely about 30 years ago and started following Celtic I have never had anything other than a warm welcome from the Celtic family, never anything less.
To me bigotry begins at home I've witnessed it and when anyone asks me why I'm a Celtic fan the explanation is simple, I'm a social climber.