[lhorie]

Nah, it's definitely the hygiene thing. Pools often forbid food and drinks at the deck for the same reason: if someone dirties the pool water, they basically need to close off the whole pool and recycle the pool water for a few hours, which is super inconvenient for all parties involved (and obviously embarrassing for the parents of the kid who made the mess). You'd be surprised at how often these things happen.

Ask me how I know :)