That's the common error people make in their reasoning. Don't look at how many of the best 2yos make great free for allers. That's like saying the best kid in under 13s rugby league will win the Dally M. Look at how many great free for allers races at two. Blackie and Quinny are two that spring to mind pretty quickly. Didn't cause them too many issues.
I also look at another horse, Composed, who won a listed race as a 2yo. Hasn't slowed him up much.
Expecting age bracketed success to transfer to open age is ridiculously tough. It's not because the horse has been cooked or pushed too hard most of the time. It's because the horse was a good juvenile. Developed early and cashed in.