You are ignoring one of the goals associated with many RPG's and FPS's... gathering equipment and upgrades that give you an advantage over the foes in the game. Valuables are more likely to be behind locked doors than open ones. But in most games of this type, you start off with the weaponry that should allow you to get past the locked door, keys be damned. This is no different than the 'impassible' barricades that even a 5 year old could move out of the way, climb over, or climb under in real life. Designers should be tasked with coming up with more imaginative solutions to keeping the gamers out of areas that shouldn't be accessible without destroying the sense of immersion into a 'real' world.
As to your example of doors within 40 feet that can't be opened. If it's a locked medical supply room that you know contains an epi-pen and a coworker is on the floor in a state of anaphylaxis, is that locked door going to stop you?