The thing is, stars don't start at the top.
Will Smith did a sit com and rap, Eddie Murphy did stand up and Saturday Night live, Denzel did a whole range of lesser films before he become an Oscar winning star.
What hasn't happened yet is an asian american actor who starts out in something else (TV, music, comedy etc.) and ends up leading a blockbuster film.
Very true. There really isn't a secret council of entertainment rulers who actively decide to promote this or that based on any criteria. Or, really, the secret council is actually all the entertainment consumers in the world who just watch and go see what they think they will like and movie producers try to put out what the people already are telling them that they like by the fact it does well at the box office or in the rating.
Only by the time it comes out, everybody's into something else.