Check the statistics on OTD kids. The major abused substance is alcohol, and many started at surprisingly young ages. Why put these kids at risk by offering them alcohol when they’re too young to foresee the consequences? I wouldn’t be very happy with a rebbe who gave a teen-age bochur booze.
For that matter, I wonder about Purim too. I’ve seen some high-school kids who were stinking throwing-up drunk on stuff they drank at their rebbe’s. Remember the days when your zaide said, “Shikker is a goy?” Since when have we Jews started up with this stuff?