Nobody here has stated that for them, it is about moral uprightness or the like.


But seriously, my reason is I don't like drinking or being around people getting loaded, and those I know who game do not know how to cut themselves off, so it is not even allowed, for the various stated reasons: kids present, driving afterwards, drunk rules lawyers, etc.
Drink if you want to, but PLEASE don't get on the road if you do.