The issue of diversity on TV isn't something that I always care about as I am more comfortable with an all white cast than I am with one black or Latino sticking out in an all white cast. However, on POI it is kind of glaring since they started with a prominent black character and pretty much killed her off for no reason.
I can't help but notice all of the parts that the show is adding on that may see like one time appearances, but you know with how the hour's story goes along, that the character will come back in another episode or two or three. However, none of these new characters are black and they easily could be in a show that has the ability to not really reference race.
The new crime lord is a black guy and the chief of detectives is something ambigous, but Root could've been black or Latino, as could a lot of the operatives that come and go, but for whatever reason, they aren't and that is really puzzling to me, but in many ways, not really. It's almost typical.