Yes, I agree getting a longer barrel will not get better accuracy.
And it annoys me to no end that some players transplant their Counterstrike or whatever FPS beliefs into a Nerf game.
Dude, it isn't just some videogame fantasy. The idea behind a nerf barrel is that for as long as air (compressed or plunger generated) is pushing on the dart, the dart is in the barrel. But the second the plunger stops moving or the compressed air has all been released, you want there to be no more barrel at that point. So for some guns (HAMPS, big blasts, PASes, +bows, etc.) the absurd ammount of air requires a longer barrel.
Is my explanation making sense to anyone else other than me? Or am I jsut completely off base?