When I see someone working out, at the gym, at the track, wherever, I really don't judge them. I generally think, "Oh, good for them."
It's hard to know what people are doing, so I don't pass judgment on folks. Here's an example from my personal experience: Each week, I usually do 2 days of HIIT, 2 days of weights, and one day of steady state cardio. Like the individuals you disdain, on some days I get on the treadmill and run at 5 or 5.5 for 30 - 40 minutes. I do that because I recently achieved a goal of running my first 5K. I want to build endurance and do some more of them, and sometime I just plain like the feeling of loosening my legs in a run without going up to max perceived exertion. Also, if I've really burned it out the previous day with the weights and am a little sore, then a gentle, steady run is what my body needs.
And now that you don't have to be perfect, you can be good.