Sober - The point of asking the question is so that FR can cover their backsides and say they complied with the formal process requirements.
Yes, it ticks the box for an auditor. Yes, if security find some Semtex in your bag, the airline can say they were deceived by a fraudulent passenger and try to escape some of the blame for the ensuing incident and outrage in the Daily Mail the next day. No, I'm not sure what other practical benefit it achieves.