DC is doing a mediocre job at best "solving" problems halfway around the world that it has little business interfering with in the first place. I'd really hate to think how well they'd do policing Alpha Centauri as well.
It's a problem of identity. When a beign government operates domestically, it can do a fairly good job because the people are (fairly) happy with it. But when it tries to extend itself elsewhere, no matter how good the intentions, it is met with resentment at best, hostility at worst---simply because it's "them" rather than "us". That is the fundamental problem with imperialist states like the Alliance.
Which is not to say that the problems are entirely the fault of the Independents for resisting occupation. While things would no doubt have gone smoother if they had given in gracefully, there's still the problem of bureaucracy getting in the way of actually making things better. And when lines of control extend to interplanetary distances....there's more bureaucracy at work than a civilization confined to one planet can imagine, I expect.
The fundamental premise of the show is that "big government" reaches a tipping point after which it simply doesn't work.
It's possible that isn't true, but it's a reasonable enough premise to start from that I have no problem with it.