It's easy to critisize. Pilots should know the value of learning from experience
As a pilot and a gun-owner I have mixed feelings and answers to this. But for the sake of pprune I will answer with my pilots hat.
We have learned from many aviation incidents, fatal and not-fatal alike.
The idea being to take a procedure and make it safer. For better or for worse we live in a world that is complicated, and we don't have the right answers.
As of today the FFDO program has not yielded a success story, but what if it had and then this happened?
In aviation we face an unnatural challenge every day trying to keep something not meant by nature to fly in the air. We also do many things to make people feel comfortable, even if only for appearance sake.
Let's not quibble over the right or wrong of carrying a firearm in the cockpit, but if necessary (for what ever reason) how to make it more practical (like not making one stow it away when going opening the cockpit door) to make it practical and safe to have it ready for use.
Why this would happen during finals is beyond imagination, but one incident should not ground an issue, otherwise we will never fly another aircraft again if the nay-sayers of aviation have their way.
Let's follow the pilot creed and use this to make the procedure and aviation in general safer, and not further look for ways to stop pilots from keeping passengers safe.
I for one would rather have armed, suitably trained folk on board for what ever deterrent factor it serves than live in a society where we are too pacifist or scared to try and protect our society and let the wacko's win.
We have so many challenges in this industry; let's not knock attempts to address them and further handicap our ability to address them.
It is better to embrace an approach and make it more practical, than less and further hinder as all towards progress.
<open myself to flame>
For those nay-sayers out there, why don't you try and solve world piece first, then try and stop those trying to protect everyone else.</close open to flame>
It ain't easy; but then no-one said it would be.