They know, and the choices were intentional. Especially given some of the things that can drop, we don't need abundant and infinite sources of some materials. Iirc it works for a few things made from stone and wood. I'm sure they'd be open to suggestions though, so make some!
suggestion:
You will get back single piece of leather/iron ingot/gold ingot/diamond if you deconstruct leather/iron/chainmail/gold/diamond weapon/armor.
flind and steel (tool to make fire) - 50% chance of either iron ingot or flintstone
shears - iron ingot
bow/fishing rod - single stick/string for both.
shield - wood and 1 iron nugget.
wooden/stone tools can have higher return rate.
Also deconstruct cooldown should be reduced to one minute.
This way we can get materials from what we don't want.