Many of the artists that work for the Big 2 are hispanic or european or middle-east. The problem is simply none of the current fans are interested in reading about new characters unless there is a legacy aspect attached to it and even then it's dubious.
But they still do not know how to write a character like JS. To me, this could be read as a case of people with limited life experiences, where they do not really
know any African Americans on an intimate level, so you get the aforementioned old Spike Lee nonsense, or worse, crap from Tarantino movies (or the caricature Sam Jackson has become in too many roles).
Writers have built on Hal Jordan from his Cold War, by-the-book adventurer days, to the Denny O'Neil period, and forward, all based on his modest, space opera origins, so why not JS?
His introduction was forceful, politically hot for its time, and provided an excellent template to use as the African American experience (in fiction), indeed, the comic book superhero experience both changed rapidly as the 1970s ran its course. But a significant level of growth simply did not occur then, or in the decades to follow, hence his fate today.