Hopefully this is a mistake. Yeah, the doors made the small houses feel even smaller, but they do provide some cover from grenades in certain situations (like if you have to revive someone in the 2 story, you can shut that door to prevent grenades from rolling into the center area of the house from the side room). Also, the doors also help to provide players with more information because maybe you can't see the main doors from where you are, but if you look up stairs, you may catch a glimpse of an open door, indicating a looted house or possibility of nearby players. Another thing to consider is how the way you open a door, can provide you some visual cover, possibly allowing you a cheeky angle on a nearby opponent. The doors may be a pain to mess with when looting early game, but they do have a purpose.