I agree with this.
There were so many missed opportunities. We're never really told where any of the major characters came from (except Tubbs) and how they ended up in Miami. OK, it was implied (I think in Made for Each Other) Zito was from Staten Island but once again, how did he end up in Miami??? And Gina has an Italian last name, but it turns out she is Cuban. Was her aunt married to a man of Italian origin? Did she live in Miami from the time her aunt brought her from Cuba? Did Trudy come from the mean streets of Overtown? I had a fixed idea Crockett grew up near the Everglades or the Keys (which was never said, I just assumed for some reason...), maybe because his hobby was fishing. For me, just giving them a background would have increased some opportunities for storytelling inspirations.