FairwayDodger
Money List Winner
It is the "establishment" mentality along with part of the sectarian aspect of Celtic fans/players were predominately of Irish heritage, of which I have first hand experience of being asked which school I went too when I went for several job interviews when leaving school.
Sadly it cuts both ways. I started a job years ago and new colleagues commented that I was the only protestant (actually I'm an athiest FWIW - couldn't care less about protestant/catholic nonsense) the manager there had ever employed. In an unguarded moment after I mentioned supporting Rangers he remarked "I thought you were a tim?". He wasn't joking.