As I see it, there's basically two ways to effect change. One is to trust that the abstract entity 'government' is a benevolent being and that we have but to supply a couple of good arguments to make it do the right thing.
The other is to take matters into our own hands and to force them to make those decisions that we want, if only by making a clear statement of: "if you want to keep your little seat of power, you better do these things we want or we'll vote in someone who will".
Approach one is naive at best: even if people in government are generally willing to make the right decisions (which is by no means a given), identifying what decisions those are is a hard problem to begin with, and that's is compounded by the fact that there are many more forces at play than mere morality (pah!).
Positive change doesn't just magically come about because many people sit on their couches being really, really in favour of something. They come about when many people get off their couches and take action. Our governments fail us because we've largely forgotten that democracy is more than going into the voting booth every 4 years and choosing between bad and worse.
That is an uncharitable way of putting it though. There are some very good reasons (or excuses) for our failure to fulfil our part of the contract in a healthy democracy.
If you work 12 hours a day just to make ends meet, live paycheck to paycheck, and all you have energy for in the evenings and weekends is sitting on the couch and absorbing whatever dribble the telly feeds you, it's hard to summon the willpower to improve your long term perspectives.
Similarly (though I don't mean to equate the two scenarios), if you're a privileged software engineer who makes 6 figures, it's hard to summon the motivation or even detect the problem. What do you mean? What problem? I'm doing fine, and so do all the other (privileged rich) people I know.
You know what? I started out writing this to disagree with you, to place the blame squarely with a lazy and inactive citizenry. Now... I'm not so sure any more. So thanks for giving me something to think about!