I like Strava too. I don't do much actual racing on segments (though I do a little on familiar trails). I do use it to track my miles - but even then I don't use it on every ride. I like racing myself on some segments and just seeing how fast others can ride it. Its a fun diversion when riding solo.
I just got back from KT, some of the times on segments up there are insane. I would love to ride with someone who is that much faster than I am riding some of those. I could definitely learn something there.
Another use - there's a local park near my house that has some new trails on it that need traffic. I created segments on Strava of those trails and that way I can not only "announce" those trails to local riders, but also kind of watch how often certain trails are getting ridden.