Man, for how light hearted this series is, it's so refreshing to see an anime that doesn't sugarcoat death and refrain from showing women getting beat up in fitting context.
I'm sick beyond belief of the double standards and misgiuded morals from today's media.

why they don't wish to kill boo??? lolzzz

Unless the one they are wishing to be killed by the dragon balls are weaker than the dragon ball's creator, then it's impossible.

probably because it's sort of their responsibility considering vegeta, goku and gohan all made mistakes leading up to the revival of boo