Yeah, Right?! Like...humanity that maximum potential was Muten Roshi, even not someone like him, but Doctor from Red Army....and he was able to kill Sayajins. I was close to drop DBZ when was watching Cell arc...it was so...it was like filler, that what I was thinking.
Majin Buu indeed has sence and it at least could be normally explane. But scientist from Earth with lvl of tech that just could get to the moon, has no chances create weapon that is not just stronger than Freeza, but stronger than Sayajins. But wait, as I remember all four androids was stronger than normal Super Sayajin