To think that people do not realise this waste their precious redstone

yup

its not like the mob in the game isnt coded to go to holes, duh, and also most players are busy with doing anything else other than killing mobs which is why they make redstone traps so that to prevent mobs killing them while they're doin something else

I am talking about home protection

You should have enough common sense to understand where you should and shouldn't apply this simple trick