Perhaps because they're the only ones there too weak to be able to fight him (though Krillin did a good job saving those people in the anime and Tien maybe could've killed Cell with tri-beam/kikoho).
Krillin should know better. He was bullied. Tien should know better too. He has three eyes, so he's almost a four-eyes, like Peter Parker when he got bullied by Flash.
Sir this is a dbz section. We only speak of turtles, frogs, dinosaurs and dragons here.
I might've seen that news before, but I forgot. Did you watch season 1?