Please explain how a concealed weapon in a holster with multiple safety features is going to accidentally discharge or otherwise make a room less safe just by being there.  

Most "accidental" discharges are actually negligent discharges by people with shitty firearms discipline (fucking with their gun, not ensuring the chamber is clear, etc).  Any modern firearm has multiple safeties aside from the obvious external safeties to prevent the primer from being triggered by anything other than the chain of events started by intentionally squeezing the trigger.