Because they needed him not to for the plot to continue. It's called a plot hole. It happens.

Man in a hole and man in a tub are plot devices used for short stories. Man in a hole places the main character in some sort of sticky situation he must get out of. Man in a tub uses an ordinary, yet random, event to teach the main character a lesson.

I wonder this all the time. I assume it was a plot-hole made by Stephenie Meyer.

This is likely a plot hole by the developers. They wanted to give Samus a personality, and make her more attractive to Japanese males (shy, weak, fragile, needs a man to rescue)

So they butchered her character. Not to worry though. I hear in the next game, they are going to try and make amends for this abomination.

Again, it was a Plot Hole

it is about unicron rising and getting revenge on the atobots form defeating him and getting sucked in to a black hole and reancarnating the fallen