4greens
Fitter two, on a carrier you do not flare to land. If you did you would miss the wires.
I rather think that's the point, though it's not immediately obvious: read the saying as: (If you) flare for landing, (then you must be a person who has to)...
Always ignored the ability and courage of female pilots, of course, and not sayable now (good thing). But it has an imagistic and rhetorical shapeliness.