Fence hitboxes are inconsistent

I know i've been making a lot of hitbox bug reports, but this is the last one (i think)

manyblocks have pretty detailed collision bounds to match their models, like hoppers and anvils, however, fences do not, and are just a solid cuboid (or two or three, depending on how it intersects with other blocks). Cobblestone walls have similar models, and their pillars get their own collision that's a bit thicker than the "wall" portion of the model, so why not give fences the same treatment?