Because "the public" isn't one person or even one cohesive group. Some see the manipulation, and point it out. Others don't see it, or ignore it when it's poi

Because "the public" isn't one person or even one cohesive group. Some see the manipulation, and point it out. Others don't see it, or ignore it when it's pointed out. And why ignore it? Because they don't want to believe it's manipulation, because it promises large numbers of dollars, and they want to believe that those are real.