As for the reason, it is pointed out that it was not appropriate for armored warriors to shoot during the Sengoku period (period of warring states), that it was cumbersome to shoot from gun crenels in tactics, and during peaceful periods the form and style of shooting was inherited through tradition and were rigidified.
その理由として、戦国期においては鎧武者による射撃に適さないことや鉄砲狭間からの射掛けにおいて邪魔であるという用兵上の事情、泰平期においては流儀による形態・射法の継承による硬直化等が指摘されている。