Items like torches, redstone dust, doors etc can be placed on top of hoppers.

More like a feature not a bug 😉

The hoppers under a bed thing is clearly a secret feature to suck the soul out of the player and create a Herobrine. x3

Not sure if this is a feature or a bug. I know rails are meant to be placed.
Waiting for Mojang to comment on this one.

I'd say ti works as intended. Being able to place additional items on hoppers harms the game in no way, where as not being able to place items on hoppers would prevent rails, pressure plates, and redstone - which limits the amount of innovation and creativity such an interesting block would allow.

If this is not as intended, then as intend should change to this.

@Corgano - of course, we're not saying to remove everything that goes on top, such as rails. However, that doesn't necessarily mean it's logical for everything else to go on top.

I disagree that redstone is required to go on top as that doesn't affect any mechanisms other than the possibility to make them more compact, which isn't critical. Weighted pressure plates on the other hand has a very good use on top of it because it can be used as an alternative method to detect if the hopper is full and similar contraptions.

So in short, rails and weighted pressure plates need to be place-able on the hopper at least.

From what I understand, the blocks have a class or attribute they inherit that requires them to have a block under them. Instead of the complicated programming of adding an exception to only allow certain blocks of this class, why not just allow them all? It should be left as is for simplicity and flexibility.

If you don't want a bed, or red stone, or slower pots on a hopper, then simply don't place them on a hopper. Problem solved.