I suspect there are very few folks who's primary mission is miles. Rather, it is often the means to a different end, more terrain seen, less time away from home, opportunity to get into remote areas, etc. I doubt there are any who has a singular focus of miles at the expense of everything else, well maybe one or two. It would be far easier to just get on a treadmill and walk for hundreds or thousands of miles if miles were the only focus. I do think there are many who look at how other choice to spend their time on the trail and evaluate that choice through their experiences and preference completely missing the reasons that others have for hiking differently.
One final thing. Brian alluded to this above. Night hiking offer a whole different experience. One of the coolest moments of my thru hike was hiking back south from the Canadian border at night, above tree line, full moon, cool temperatures. It was absolutely magical. Same thing with hiking before sunrise. Yes, it is a great strategy to put in the miles but it is also a great opportunity to watch the wilderness wake up and start the day.