Really? You've never flow at night and noticed it is actually easier to see them on a moonless night and you won't confuse them with ground lights?
Or are you imagining that IFR flight means you don't look outside. That's only in simulated conditions when yo use a view limiting device to prevent you from looking outside. Check out what the FAA says about your see and avoid responsibilities:
When weather conditions permit, regardless of whether an operation is conducted under instrument flight rules or visual flight rules, vigilance shall be maintained by each person operating an aircraft so as to see and avoid other aircraft.