1. Kami can revive Shen-Long and make wishes immediately.

We find this out at the start of the 23rd Tenkaichi Budokai arc. All he has to do is haul out the dragon statue, have Mr. Popo glue it back together, and breathe life into it again. He even allows Goku and friends to bypass the one-year wait, and they use the Dragon Balls again that same day.
2. Mr. Popo can gather the Dragon Balls in one day.

Fast forward to the Freeza arc. In the middle of Freeza and Goku's fight, Kami telepathically reaches Kaiou to tell him Mr. Popo has gathered all seven Dragon Balls. Wait, what? Kami has been alive for less than one day, which means the Dragon Balls have also been around for less than one day. The Dragon Balls were last used to revive Goku, the day before Piccolo's death, and they scattered all over the Earth. So it's not like they were all sitting in one spot or anything. Mr. Popo probably zipped around on his magic carpet and gathered them all in a matter of hours. We know he didn't use the Dragon Radar, because Bulma had it with her.
Unless Mr. Popo grabbed a second one from Bulma's parents for some reason. Like, he popped into the house and was all like, "Hey, can I borrow that Dragon Radar for a little bit? I'll bring it back, k thanx."
But we know that didn't happen, because that's fucking stupid. Hey, doesn't Goku pull an Ultimate Dragon Ball out of that dinosaur's stomach later? How did it get into space? Why does the same specie of dinosaur exist in space?
3. Kami actually wanted to do something about Piccolo.

Because he tells Goku. He says, "I want to take responsibility for Piccolo." Then he even steals a human body and learns the Mafuba to deal with him.
He steals a human body, learns a suicidal technique and goes through every round of a tournament in order to personally deal with Piccolo in a needlessly risky and incredibly complicated plan.
4. Hey idiot, why didn't you just revive the dragon and have Mr. Popo gather the balls so you could wish for Piccolo to be sealed up again?

Oh. I - I guess there wasn't really any reason to not do that. At all.
Unless...
5. But maybe Kami can actually see far into the future, and knew that by letting Goku fight Piccolo, he was actually saving the universe?
Here are the things that would have happened if Goku had not fought Piccolo at the end of the 23rd Tenkaichi Budokai and let him live.
1. Raditz would easily kill Goku and come back with Vegeta and Nappa to destroy all life on Earth.

2. The planet would be sold to aliens.

3. Those aliens would eventually be killed by Babidi and Dabura, who would revive Majin Buu.
4. Babidi and Buu would easily conquer the universe.

We know Kami has some amount of clairvoyance, because he's aware his own life will end one year before the Saiyans' arrival. He must have seen years into the outcome of his actions and determined letting Piccolo go was the right thing to do. That actually explains everything. Kami can just see into the futu-
Oh.
6. For that matter, Kami could also have prevented the entirety of Trunks' future.
Why couldn't you foresee your own death a year before that happened? You didn't think it would be useful to mention, "Hey, guys. I'm going to die in a year. There might be some new threat headed our way. Or I might just be old. Either way, it's probably a pretty good idea to consider fusing with Piccolo at this point, considering he'll die too. Or, I don't know. I just thought I should mention it in passing. Whatever."
But I guess everyone was too busy that day to listen.

Must'a been a pretty good show.



