This. DB started out as a gag manga, and is still one at heart. Toriyama and Toei just want to tell a fun story without caring too much about plotholes.
I think we should just be glad that Toriyama is so honest about his creative process, unlike such writers as for example George Lucas, Nintendo (Zelda series), etc., who pretend that they always have everything planned and that there's no inconsistencies in their stories.
Like Krillin both having a nose and not having a nose.