I used to get annoyed by that too. As well as the big lipped black boxer that used to fight in te tournaments.
But i forgave it because DBZ sticks to a sorta old and very traditional style of Japanese animation. and besides, Piccolo was fucking black and a badass. I don't care what anybody says… Piccolo was the definition of Angry Black Man lol
Like, "leave me the fuck alone. Got me away from my home planet defending these goddamn Japs. just let meditate on my rock. Fuck."