NYPD Blue? The Shield?
You're asking for Star Trek
to become something it fundamentally isn't and never should be. There are already fifty zillion dark and cynical shows on TV and five hundred gajillion dark, dystopian science-fiction futures in both fiction and literature. What makes Star Trek
special is its optimism, its inspirational nature. It's important that there be at least some
fictional franchises out there that try to do something different than the same old cliched negativity.
True, there have been times when ST has pushed its heroes to darker places -- Sisko in the Dominion War, Janeway in "Equinox," Archer in the Xindi arc. But there have always been limits, and those have been the exceptions, not the rule. If what you want to see are protagonists that are always that dark, or even worse, then you do not want Star Trek
. And there's no shortage of cynical, ugly, negative franchises out there to give you what you want.