the hopper is in the wrong place

i don't know if this is a bug but why is the hopper in the red stone tab, as far as i can see it doesn't have much to do with red stone, it doesn't but a signal out, and it doesn't change if it receives a RS signal, all tho it would be nice if you made it so if it receives a signal it can unload full stacks at a time or work faster in some way dependent on how strong the incoming signal is. but i think the block would fit better under tools or decoration