Jungle buff camps always living with 1 hp?

This happens every single game that I jungle, and the extra hits you take and the time you lose really adds up and can hurt you, especially on the first clear. It seems that the bladed armour mastery and gromp poison won't kill red/blue buff and they're left at 1hp, requiring 1 last hit. I think this should be changed, doesn't make much sense to me.

EDIT: Forgot to mention that that jungle item DoT also doesn't kill them.