There are two aspects of GPS tracking as I see it. I use it to track accumulated distance and elevation. I figure I have to do it religiously if any of that data is to be reliable or of any use, and Strava on my phone seems to be the most convenient way of doing that.
The other aspect is mapping. Ever since I first learned to drive, and drove from Portland OR to San Diego the following week, I have wanted to have a map not only to see where I was going, but where I went. I'm not sure I can explain why, but it's something I've always wanted, and finding these apps has been very satisfying.