Since I started this thread I though I ought to share my story as well.

So I'm one of those DKH mentioned that was dragged along until graduation by my thesis advisor. I guess like many others, I started my PhD with high hopes and dreams. However, the more I learn about the field, the more unmotivated I became. After 4 years doing the work without much reward in term of success, I was burnt out. I wish to have nothing more to do with the project anymore. My funding ended and I got a job doing something slightly different in the same field in another department. It's not until another 2 years later that I finally submitted my thesis and defended it.

Now I hold a post doc position but in reality quite dissatisfied with the work. Perhaps it because I know the result will only interest a handful of people in the world and most probably wouldn't have much impact to our society. Perhaps it's because my own expectation was too high and unrealistic. Or it could be my constant wonder of what it's like outside of the academic fence.

My current exit strategy from academia is to use the relax lifestyle of a postdoc to build up my iPhone app business. Hopefully achieving financially independence. Then perhaps I will have the freedom to pursue other interest. Something that will have a more immediate impact in our society than the old dusty scientific journal ever will.

So I'm very glad to see so many people who have positive experience with their PhD. And regardless of whether the PhD have helped them in their later career, they are happy with their decisions. As for myself, I'm still too fresh after my PhD to be able to reflect on whether I'm happy with my decision to do it.