"chords in standard tuning can add too much harmonic information to modal tunes" That may seem "logical," but if so, many real folk musicians in Europe and America thought the "illogical" sounded good. In blues, for instance, the routine (and as far back as blues can be traced) use of I, IV, and V wasn't based on avoiding "too much" harmonic information relative to close to 1 2 b3 4 5 b7 at all, and similar is true of much European folk music.