I very much like the show, as coming from a Green Arrow fan. I even wrote a review in our school newspaper when the show first aired. I think it's a good show, mainly because it develops for people who have no clue who the Green Arrow is. It also adds in other significant characters like: Deathstroke, Cyrus Gold, Grundy, hell, I even saw an easter egg of Harley Quinn in the show.
Yeah... this is a common trope in bringing comic books to film, make everything dark and grim to make it "Realistic", in essence DC is making all their heroes be more like Batman. Green Arrow is now Batman, Superman is now Batman, Flash is now Batman... Why can't comics just be fun again.
Mos isnt even realistic, its just darker that The Dark Knight Trilogy, in TDK trilogy you have Lucius Fox and Alfred making jokes all over the movie, then you have The Joker and the guy is making fun of Batman all over the movie, Catwoman is making fun of Batman, i mean, this movie take itself too seriously.
DC being Batman Centric isnt a shock, the problem is that is getting more obvious.
I mean Clark Kent was darker and more serious that Bruce Wayne.