Just because the horse bolted once does not make it sensible to leave the stable door open now.
This debate is surely now moot. It went the rounds in the eighties, and it went the rounds in the nineties. If cabin doors had been barred as a matter of procedure for all that time 9-11 would never have happened, it would not have been worth trying and then all the millions wasted on window dressing 'security' and all the inconvenience and stupidity of the last couple of years would never have happened. And Oh yes! A large chunk of the aviation industry would be a lot healthier financially than it is today.
Oh, and another thing, my kids would still be able visit the occasional cockpit, after the appropriate checks.
A plague on all of you who put your vanity or your comfort above the safety of your passengers.