i don't really have a problem with the mela, it isnt really promoting anything bad, just music and a nice day out for students and their families. I went to Guru Nanak school for 6th form, and i attended many relgious events there and it was nice to have a cultural event to go to, it made a nice change.
I think it's important to give the students variety in what they see. A bit of light hearted fun does not take anything away from the school.