Sealing up the cockpit completely from the rest of the aircraft may sound like a good idea, but it creates other problems too. Pilot incapacitation, for example. What if one guy gets incapacitated & you have a bunch of other off-duty colleagues travelling in the back? What about resource management then? Yes, you can say 'just too bad, it's worth the risk'. But then it's really all a balance, isn't it? It's no secret that the statistics are that incidences of crew incapacitation are far, far higher than incidences of the sort we've just seen in NY & DC. Or what'll happen if you need to go behind to take a look for yourself? Like your pre-takeoff de-icing visual check of the wing? Or even some kind of problem that developes in flight when you might want to send the F/O back (time permitting) to take a look? So where do we draw the line? You solve one thing only to have open up a bigger can of worms for yourself. What happenned on Tues is pathetic & shameful to say the least, but in the bigger picture, the chances of this happenning again are more slim than having some of the other types of in-flight problems.