If someone wanted to kill Hiro, wouldn't it be easier to kill Kaito and perhaps Angela Petrelli before Hiro was born?

However, if you're on the wrong timeline, you might just kill them accidentaly after Hiro was born... And it won't change anything in the present.

Just a thought.

How exactly would killing Angela have anything to do with Hiro not being born? Who else other than Hiro has the ability to travel through time to accomplish such a task?

And most of.....HUH?

why would anyone want to kill Hiro?

And I'm sure that you can kill Hiro by killing Kaito, but it would just be kind of dumb...

It would cause a rift in the space-time continuum.

If Hiro had never been born, there would be any reason for someone to go back in time and make sure he was never born.

Paradoxes like that can't really exist.