WoW doesn’t have housing because erotic role play isn’t widespread enough to justify implementing it.
Final Fantasy XIV got housing because ERP was so pronounced, that cities were spilling over with players that were emoting eachother in their underwear every single place you turned, blocking auction house areas, lobbies and generally being an eyesore.
FFXIV still has this problem but it is less severe with the housing, a problem that WoW isn’t having.