"Reasoning" by analogy is one of the weakest forms of "logic" -- especially when the cited "analogy" isn't really analogous.
The bullet in flight is more nearly (but not quite) analagous to the boat driven sideward by water currents (not the wind) or the aircraft flying east in a north wind. Neither the boat nor the aircraft has the insistent "I gotta go this way" resistance to the cross-wind that the gyroscopic effect of its spin gives the bullet. Both the boat and the aircraft go sideward at exactly the speed of the body of water and air that they're traveling in. Neither has a connection to the ground, so the sideward speed of each, relative to the ground, is solely a function of the speed of the medium surrounding it.
When the bullet flies across the prevailing wind, how much of the wind blows past it? Ah, there's the rub! (This question doesn't even apply to a boat crossing a river or an aircraft flying perpendicular to the direction of the wind.)
An object tethered in some way to the ground (or a body of water) and secondarily subject to the wind simply isn't analagous to the bullet, the boat, or the aircraft, relative to the way that the wind affects it.
