I wanted to develop my own for years before I finally got around to it last year. I always felt like I was only doing half the job just taking the picture. I wanted to know that I could finish the process myself. And like Indofunk said, it still feels like magic when I pull the reels out and there are images on the film. It helps me take a little more pride in my images.
It's why I want to start printing my own, too, but that's not as easy to start as developing was. My current circumstances don't really allow for a darkroom at home, though I'm hoping to arrange some darkroom time at the college where I teach.
Having said that, I chose "it saves me money" because it's also a major concern and it's the answer on the list that is closest to the truth. It's just that the 'truth' is complicated
It's not really the whole reason I'm a photographer, and I don't think my results are better than the lab results (partly because the lab I use is really good.) I still have so much to learn about it and it's nice to be able to have control over the whole process from soup to nuts (once I learn printing), but when it comes down to it, I also don't mind relinquishing some of that control to let someone else do the processing sometimes. I don't feel the need to always do it myself.
And now, those 5 rolls of TriX are staring at me, wondering why I'm yammering on about processing but not doing any!