Ok, rephrase it to: a knife is not a tool for any pilot.
Of course mechanics should have a certain array of tools to do their work properly, although all this tools should be in a hangar beyond security already. Or are you telling me all mechanics should from now on be able to pass security with knives carried on themselves as personal items?
As a passenger, knives are allowed in your luggage which goes in the hold. I would imagine tools for a maintenance outfit would have to pass security in a similar way, although I'm not sure about that.
Btw, I'm passing security myself everyday, if they find something in my luggage which is not allowed to pass, of course I would try to reason with them, but from my experience they're not the smartest of the class and therefore the discussion will always be difficult. Early start of the day can sometimes be ruined by an arrogant security agent, it just happens all to often.