Diversity is used as a sales gimmick in Hollywood. That's a fact. It has become part of the promotional package for the movie to pat themselves on the back about diversity and how this or that is some great leap forward for mankind.
Diversity may indeed well be a sales gimmick. That pattern, emergent as it may be, argues that diversity in film is worthy of celebration. Isn't that how the free market works?
Seems cynical to suggest otherwise - that arranging a diverse cast into an entertaining movie will have no value.