Had they casted Northern African/Middle Eastern actors for all the major roles in a film like this, good chance it would have done worse.
nolan's whole point is that having an all white cast doesn't considerably change a movie's chance of success over that of a film with a more diverse cast. you ask whether having someone like dwayne johnson in the film would've helped, and like, yeah, who knows. what i do know is that his star power doesn't necessarily guarantee a movie's success despite the fact that he's one of the biggest actors in hollywood right now. see: baywatch.
if a movie's cast doesn't considerably affect whether it is good or not (yes, great performances can improve a film, but these performances are arguably limited by writing and direction) or how successful it will be, then why not cast with diversity in mind? you say that people want to see themselves reflected on screen, and yes, that's true to an extent, but as a person of middle eastern descent it's not like i refuse to see movies with white people in them; similarly, i don't think white audiences will never watch movies with people of color in them, or lgbt+ characters. relatability isn't the be all end all. in the end i think we can all agree we just want to see things that are good. like, i don't enjoy breaking bad because i agree with the protagonists desire to have a crime empire, i watch it bc it's well made and the themes are universal. i believe get out is the best performing film of the year? yes, the movie deals directly with race, but i think it appeals to so many people for more than just its cast (although the fact that it had a diverse cast may also be an appeal, because that is something that is actually fresh in films these days).
yeah. so it's like, i'm not sure if your attitude is a necessarily helpful or good one. it feels at worst dismissive and at best defeatist.
also, you probably know this already, but dwayne johnson isn't white. so while you may say he is one of the exceptions, i think his and others' success is proof enough that diversity isn't box office poison.
galedeep: if i'm getting into too much sd territory lemme know and i'll cool off.