If you are listening to an acoustic set of music with a un-mic'ed drum kit in a small venue and you are hearing washed out mono with 80% room sound then the acoustics of the venue suck.
Most bands play in rooms with poor acoustic, granted, but the ratio of direct to reflective sound actually favors the reflective sound more in good acoustics. If you are standing 20 feet away from a kit, say in an acoustic jazz concert, there is not going to be any left or right information, just a single point and whatever is reflected off the room surfaces.
If you ever go to an orchestra concert, you will also notice there is not much clear left or right information even though the orchestra angle is huge by comparison, it is mostly just a wall of reflective sound. Unfortunately that wall does not record well.
And in rock concerts, the audio is almost always mixed mono for the PA anyway.