"It is not primarily the sex/booze/drugs that surround this event, as problematic as they might be; it is, rather, the flaunting of affluence, assuming exaggerated expenses, a pursuit of vanity for vanity's sake - in a word, financial decadence," Hoagland said, fed up with what he called the "bacchanalian aspects."
Read it again, this time in context.
I did, in context as you suggested and it seems that the behavior may be a reason, but it is not the primary reason, for his cancellation. the expenditure is.
There are two letters on their website (pdf files), one sent before their spring prom this year and this latest one. After reading what the seniors had planned for the May prom (which apparently occurred, I can very well see why they cancelled the prom this year
LI was once GOP territory but now I think most of it has gone Demo. Gee what a surprise.
So even if there is no prom, does this stop the disgusting permissive parents from renting a house or boat and buying the kids booze anyway??