>>75662347He does play around a bit when he's toying with the U6 Saiyans but yeah, it mostly comes down to it not really being his style. Goku's first encounter with finger beams was the Dodonpa taught by the Crane style, a direct rival to the Turtle style that was evil in nature because they utilized martial arts for assassination, hence the efficient and lethal finger blast compared to the Kamehameha.