I reckon there's quite a few reasons. There seems to be quite a lot of sikhs and hindus who support man utd; you always see them at OT. But I reckon quite a lot of ethnic minorities might be quite 'intimidated' if you will. I personally, despite being a black muslim, have never been intimidated by football and have had a season ticket for the last few seasons. I don't drink the alcohol, don't go into the pubs, don't wat the food inside whl etc. But I make it work and I love it.
However, I remember watching a show a few years ago; one of those appalling day time shows you watch when you are home sick. They found 2 fans, one black/indian ( can't remember) and one white who both had a season ticket at the same club. They did them over, changed their skin colours for the day and both noticed marked differences in the way they are treated at the match. Make of that what you will.
Not many Muslims get in to WHL,I wouldnt have thought.