Even if you had a string quartet playing in a small room, you would not put one musician in each corner of the room. The "stage" approach emulates "being in the band", not a small ensemble performing in a small room.
Just for kicks I played my "one instrument per channel" LA Guitar Quartet SACD yesterday, and I must say I much prefer "audience" mixes (i.e. instruments/vocals from the front, ambience cues from the surrounds). Thenagain, I never played in an orchestra so may be "stage" mixes just needs to grow on you.