Why are do soo many actors fail, to become great?

[Isaiah Butler]

Other than an obvious point that you may not have the look. How can I prevent from coming like all of the millions of actors out there that know one knows, that never become prestigious? Why do they never make it any where? i DONT want to be some sad looser on some unheard of casting site, or youtube making videos and getting low level jobs . I'm just starting out, and I've done 1 play and 1 musical last year lead rolls.The play was a Christmas play/The life of Jesus and I played Jesus. The musical was The Magic Flute, and I played Monostanous the lead villain. Now i auditioned for my first film and beat two adults and a few teens for the roll I am currently cast as. Im cast as Jake, one of the bad guys. Its slated for release on March 2013. It's no hollywood film, or anything, but its a film none the less and will have a public and private screening at a theater. So we are pretty much done and I'm looking for my next gig, I really want to tryout for a character in the upcoming holly wood film Divergent being shot in Chicago. Will I need an agent to get into this audition? I'm planning on going in to an open call near me to get an agent. I'm in touch with Joel Courtney on twitter and a few other teen celebrities, they found me. I just set up an account and twitted some stuff and next thing I know I'm being followed. My twitter is @IsaiahTButler. So please answer these questions and leave some advice, and don't forget the main question in the title. Also if you want to know more about me please visit my website isaiah.mixform.com feel free to comment on any blog posts.
I'm 16 years old and I'm ready for this, i know the headaches, and work and effort. I also know theres much more for me to learn. My passion at first was just the pure enjoyment and love of acting. No its developed into a passion to one of the best. Winning Emmy's and Tony's and sometime soon my first Young Artist Award. I don't care for fame and riches, matter fact if I worked at McDonalds and still got to be in Big movies with the greats, such as Denzel Washington, Cuba Gooding Jr. and others, while being the best I can winning awards, but not making millions I would go for it! My parents say its a pipe dream and i'll never make it, or their trying to except the fact that I'm going to be a bum. I haven't gone through all of this emotional scaring just to give up, so please someone help.