Buttons, levers, ladders and tripwire hooks can't be placed on sides and bottom of redstone blocks

I see no beneficial reason to attach those items to a block that's always powered.

Yes, makes no sense to do that.

Buttons, levers and tripwire hooks power all the blocks they are touching, not only the one they are attached to.

I don't understand what you are trying to say, they allways touch 1 block

Levers, tripwire hooks and buttons power the block they are attached to/touching, but they also power redstone, pistons, lamps, doors,tnt and other blocks below and to the sides... Like this: (R=redstone block, L=lever, .=redstone dust powered by the lever but not the redstone block)
Sideways:

RL.
.

Front:

.L.
.

You could use it to make some circuits smaller.

I see no reason why these blocks can't be placed on redstone blocks. Many other blocks, such as redstone wire, torches, and rails all work fine. Please reopen.

@@unknown: If Mojang says something is WAI it is WAI.

Confirmed for 16w15b (at least for ladders). It can't be working as intended, all other ore blocks work and redstone blocks aren't transparent (as you can easily check, it doesn't let light through).

Read 1 comment before yours, @unknown resolved this as intended, if mojang says it's intended, it's intended.

This issue is no longer present, and I suspect it was "fixed" in 1.14 when the faces of full/solid transparent blocks were allowed to support other blocks.