Im not sure that is the case. Provenical Rugby attendences are falling. I don't know the story with Gaa though (its also hard to strip fact from fiction with them).
Lower league Football seems to be growing in Britain too, so for me, it represents a growing apathy with the Premier League (maybe not alack of interest, but a growing lack of passion for it)- hence people are still very interested in football, but get there passion kicks from somehwere else. The best thing that could happen to the LOI now is for Qatar to buy Liverpool and United.