Not sure which is worst, a naff off-the-peg armani suit, or somebody waving a fictional MoD document about.
You really believe anybody with any credibility at MoD would turn up to Farnborough in anything other than a suit or a uniform?
Of course if you really are Tom Cruise or Richard Branson, then you are recognisable as important and very rich. For the rest of us, a little effort to smarten up shows respect to the people you're dealing with. It's just how it is in the heavy metal industry.
G