I think if writing and seeing where it takes you works for you, great. It has worked for many fiction writers.

Personally, I am and have always been a control freak. I get my ending first, and won't start until I have something that absolutely blows me away. Then I work backwards from that point, and that is when I draw character profiles. From there I sketch in plot outlines, do other research, and start. I'm not saying the narrative doesn't throw out unexpected detours along the way, but I always arrive at that end point.