In its boring way, USA Today takes offense because pilots want to be armed in case of a hijacking. Let the pros take care of it—like Norm Mineta, whose major contribution so far has been to insist that Arab men and Russian babushkas get watched equally.
The point, of course, is political and not technical. If sky marshalls have guns then deadly force remains in the hands of government agents, so regardless of what actually happens the principle is preserved that everything is under control. If pilots have them it creates the impression that sometimes people have to act for themselves, and who knows what that might lead to?