The outcome of this story was favorable (which is why we're reading it). I wonder, however, if there are far more stories that begin the same way but end with "You're being fired for insubordination" or something similarly negative.
If you don't have the stomach for directly causing people to get fired, or for conflict, then don't go out of your way to demonstrate how poorly they're doing their job. Find your way out to something else, and let them do themselves in.
In a difficult situation, you're the only one who did the right thing and it led to nothing. This says more about others than it says about you.
You boss got mad, yelled at you, and got fired. That's his problem, not yours. Others suffered or got fired and work wasn't finished. Again, their problem, not yours.
I think you should hold your head high and be proud. You pushed the envelope and challenged others, knowing full well that they might resist. The resulting negativity had nothing to do with your efforts and everything to do things being fucked up long before you got there. Don't let the illogical actions of others upset you, don't be depressed, and most of all, don't hesitate to continue to be proactive. The rewards may seem elusive, but believe me, you will find them.
Just because you can say "it wasn't his fault" doesn't mean it wasn't still a failure.
Figuring I would "beg for forgiveness" later, I kept working on it in secret. Two weeks later, it was finished and I launched it into the wild. They weren't happy, but let me stay.
Six months after launch my hackathon project had millions of users and had made the company over seven figures. I didn't end up getting fired, but I came close.
The world that might have been. Do you ever think it would have been better if you had gotten fired?
http://imgs.xkcd.com/comics/regrets.png
Different context, same attitude :)