Connections to the Walking Dead & other questions.

Obviously, there are at least three ways this show connects to the Walking Dead series. Firstly, Michael Cudlitz plays Abraham, Shawn Hatosy was picked up by Fear the Walking Dead to play the unruly soldier kept prisoner in that Latin dude's basment and after catching the last half of the fourth season and the fifth season of Southland on Shomi, I noticed that Officer Cooper's Narcotics Anonymous sponsor was Lawrence Gilliard Jr, who played Bob in the Walking Dead. This simply cannot just be a coincidence!
With all of that said, I feel that one show's (complete) loss is another's win. It's a god-damn shame that Southland was cancelled as a series. Of all cop shows I've seen, nothing else has come close to its grittiness, its fantastic method acting, its well-researched roles, solid script writing and camera work and the cast is simply too amazing to describe. Over time, I even got to appreciate the toxic Dewey Dudek. In fact, I would go so far as to say that the show actually makes me empathize with a line of work I am quite critical of. It actually makes me want to be a cop! Don't know if anyone feels like that...
Does anyone know the real reason why Southland was cancelled -- was it ratings? Lack of sponsors? This show was headed for legendary status after everything, comparable too other cop dramas. What bloody gives?!