Hypothesis time: the predisposition to flats is due to Big Band, Blues and Jazz music being predisposed to it. And there it is logical due to the B flat and E f

Hypothesis time: the predisposition to flats is due to Big Band, Blues and Jazz music being predisposed to it. And there it is logical due to the B flat and E flat tuning of the horns (their C is our B flat or E flat).