Right - if the only penalty to bashing/blasting open chests was the noise, as already mentioned, people could (and would) just pick up the chest and move it to a place with no NPCs nearby, then crack it open with no penalty. That's why it's been suggested (and I believe already implemented in game) that at least the fragile stuff in the chest should break as an added penalty to not trying to pick the lock. Doors of course only need the noise penalty, as they can't be moved around.
