Family members and most other non-pilots have been banned from the airline cockpit in the U.S. for almost thirty years now without too much ill effect.
The last thing you need in a critical situation is someone's wife screaming bloody murder all the way down as with QF1 at BKK.
After jumpseat involment in the 911 attacks most countries will probably get more serious about cockpit security as the U.S.has. It's not the Love Boat anymore, I'm afraid...