Even if just 56% of them become rich that's good enough a chance for me.
The thing is that being a millionaire really isn't the same as being rich.
Think about it -- if you were of retirement age today, how much would you want in assets to feel comfortable retiring? A quarter million? A half million?
Now consider the amount of time that you actually have left until then. Depending on how long it will be, a half million dollars today will very likely be equivalent to over a million when you will need it.
I would venture to say that most people who are relatively early in their careers, and expect to be able to put away the money they'll need for retirement, should expect to be worth at least a million dollars at some point in their lives -- and that won't be being rich; that's just going to be "comfortable."