In some contexts, not burning a bridge means one should leave a way to retreat from a situation. This can have the obverse effect, with a burned bridge being the one ahead of you.
Back in the late 2000s I owned a web design company building pseudo-flash websites on a proprietary platform. With two designers working for me, we cranked out a couple of sites a week. Everything was great. My cynicism however, eventually got the best of me. I started to be really vocal about the platforms community, and subsequently, its pitfalls. It was honest feedback, but not the good kind. The thought leader behind the platform and community, didn’t particularly enjoy the sound of a squeaky wheel. Well, we all know what happens to squeaky wheels. After being publicly shamed, we were no longer the preferred vendor. My two designers eventually left, and started their own company to compete with my own.
I was depressed, but it was largely my own fault. I was the fuel behind the fire that burned the bridge. Incidentally, around that same time Ethan Marcotte published (the now infamous), Responsive web design article on A List Apart. Then, Steve Jobs and Apple drop Flash and pretty much declare it dead.
I stopped building websites with flash, and started learning WordPress.
At some point in your career path, you might end up in a similar situation. In my case, I couldn’t go back (retreat) to building flash websites. I had to move forward. Don’t be afraid of burned bridges. They just might light the way to a better path that would have otherwise been hidden.