Heck, go to even Great Smoky and you'll see ALOT of signs that say basically 'Be afraid of the Bears'. Those signs are up because alot of people that would never dream of intruding on the space of a wasp, will walk right up to a bear to feed it or photograph it. Maybe you are right in that they don't think that the bear will attack them, but the point is THEY KNOW the wasp will - up to the point of exagerrating in thier minds the danger posed by wasps. And isn't that the essence of intimidation?
Yes a hardened experienced warrior will be less intimided by wasps than average people, but isn't that the point? Isn't that verily the mechanic? But lets not underestimate the ability pain has to override the logic of the human mind. I know several battles of the Civil War were influenced by the presence of hornets. Hornet stings may cause relatively little damage compared to a bullet, but they are _not_ sufferable. I can very easily see a young soldier be intimidated into doing something stupid by the mere presence of a warp (read intimidation check, 'Stay Back, bub!'), much less a wasp sting (read rerolled intimidation check. 'I warned you buster! Now you want some more of this?').