Intended or not, that's not the question.
The functionality of a storehouse is not only to add storage. S2HQ do act like a storehouse in all other ways, if you bother to check w/e building close to it.
Technically everything placed on the map and using up building space is a building. BB devs may add w/e funtionality they like to a building - no extra code needed.
Really?
Are you an owner of an EWTN or are you just trolling?
Your counter suggestion and logic are just as valid as if I would suggest all nonowner of an EWTN should have all their buildings using retro skin.