If you don't have that *killer spirit* that makes you want to go and hurt other people, or sabotage their efforts, and you think that this lack of competitive spirit, will hold you back, don't worry. Sure, there are a lot of nasty, mean-spirited people out there who will become successful. But they're the bad guys. If you're one of the good guys, hang in there.
Being creative just means doing your own thing. It means that you can live and let live, you can also help other people, and cooperate.
Believe me, there are a lot of good people, like you, out there. And they have become successful, not because they have torn someone else down, but because they have built themselves up. I started meeting these types of people early in my career, and I was delighted. I still see a lot of them.
Yeah, a lot of people may discourage you if you don't have a competitive spirit. But like so many people, they are idiots. Ignore them, and be creative!