Because people believe in it, but..lol. Writing such a title means that you don't believe in LoA. You doubt it or at least you don't believe that you really can have everything you want. And you are not the only one. You can't doubt LoA and at the same time use it consciously to win the lottery.
Another thing is that I haven't met many people who really understand LoA. When you don't understand it, you will have a hard time creating "big" stuff and even when you understand it, it needs practice and dedication to get to the level to easily achieve that.
Third thing is that you create your reality. If you don't except many people to become millionaires, that will be your experience.

Great answer Sanshi!!!
Someday , Ill get rid of my doubts too...Am still working on it!

Staceylouuu91x wrote:

People have used it to become rich and famous Stevie Nicks did before she was in Fleetwood Mac and had her own solo career she would tell herself she was rich and famous. 

 
Jim Carey used it too. He said in an interview that he wrote himself a cheque for $10m for services to acting. Look at him now

Oprah too, I believe.

I suppose it comes down to the way we are wired. Our human minds are programmed to think "realistically" or "logically". Although completely possible, if you were told you could win the jackpot tomorrow your brain would have a completely hard time in actually subconsciously believing it purely because of the logical odds. It would take a hell of a lot of work and reprogramming to make such a thing manifest that I think many people don't even bother trying.

Jay Z, Beyonce and Will Smith also use it. I'm sure that there are many many others.