The better question is: why would you have people on staff who you wouldn't trust to be mature enough to handle the situation?
I'm a mature, responsible, smart, amazing, blahblahblah person much of the time. And then other times I'm not, and my failures are largely non-malicious -- just stupid. I'd guess the same is true of all of us.
So I ask again why you would want to have someone on staff that you would think twice about giving access to beer in the office?