Yeah, and its impossible to do.
Just imagine.
If you go slow in multiplayer, then everybody goes slow, and that sucks.
You can't go slow, while everybody goes normal, and it seems you go fast.
Then everybdy would go slow.
Example, i fly with vegeta, and try to kill someone, and someone goes in slowmotion, this is gonna happen: Haha, another victim, swoops at guy, guy goes slowmotion, i go slow: WTF, i go slow, what is this.
And everybody else: hey you fool, stop going slowmotion, i can't even shoot good anymore.
You see, people start to get angry, and pissed.