The reason why the Dream Shake isn't a go-to move for the ordinary player is that they're limited to basically a single fake and lose it on the turnaround, thus making it predictable, when used too often.
Olajuwon had made it unstoppable by incorporating numerous fakes and thus forced help defenses. It wasn't him going one-on-one with let's say Ewing; he'd also attracted help from Mason, thus creating a kick out opportunity to Maxwell. For Kareem, when he'd get into the post and catch the ball, McHale needs to come in to stop the pivot, for the Sky Hook and thus, Worthy gets his running shoes in place for the subsequent pass plus Tomahawk jam. And the Lakers ran this play, over and over.