Absolutely ridiculous. El Al, which is the most security conscious airline in the world, never gave up its metal knives -- not even in Economy Class.
The knives are not particularly sharp nor dangerous, but they could cut a meat dinner. El Al had no reason to worry about them being used to take over an airplane because its cockpit doors are ALWAYS locked.
Now comes the TSA and approves a metal knife for use in front of the curtain. Look -- if these knives are not dangerous, they should be given to everyone. If they are dangerous, why would you want to give them to the people who sit closest to the cockpit?