It doesn't matter how you rationalize the calories burnt in a workout. Yes, if you walk all day long, in the winter, you will need a ton of fuel. Most of us don't have time for that. But, what's an hour run 3x a week? 3000 calories? Realistically that's a drop in the bucket. Who is prepared to run 5-6 times a week? Some people are, and some people aren't. There's also a hypothesis that doing very slow distance on a calorie deprivation diet turns on the "starvation mode" response, and loosing weight becomes almost impossible. And yes, competitive endurance athletes are slim... there are so many contradictions to deal with.
For those of us who don't have the time, short, high intensity and intervals work to round out your fitness base and definitely makes you shed extra weight. There's no way to get around it. It raises your metabolism and keeps you ready for something that is "all out". Now, if someone said "all you have to do is these three 10 minute workouts a week", that wouldn't be very sensible. The trick is variety.
Think about this - Have you ever been in a stage of your life where all you do is long runs, and then try to play a game of basketball or something like that? It WRECKS you. And how was you jump or explosiveness? Not that great.. How about if all you do is short intense exercise? That same basketball game also wrecks you because you're not used to to going for an hour. The lateral movement, stop and go is also hard on you regardless of whether you do intervals or distance.
I find incorporating different types of exercise at different times of the year works well, keeps things interesting and prepares me for almost anything. In the winter snow and ice, short days and weird work schedule makes running a pain. So, I'll do strength workouts 2-3x a week (one might be explosive work like broad jumps, vertical jumps or lateral movement drills), plus a few short intense bodyweight conditioning workouts, and climb indoors 2x a week (good social time also). How about a game of squash or basketball? Why not, they're fun and don't feel like "training" at all. When the spring rolls around, I'm sick of being indoors and it feels great to pick up trail running again, 2 or 3x a week. Add in a speed workout at the local track or some hill sprints once a week, and go hiking whenever I can, ramping up the number of miles I get under my feet.
When someone asks me how to loose weight, I normally just tell them to pick a few very different performance goals. Once they reach them they are normally pleased with how their body has changed to adapt to the new stresses. It helps if the goals are very different. For example - for women, setting a goal of running a sub 25 minute 5K, sub 1:25 400 m, doing a pull up and deadlifting 1.25X bodyweight is attainable - and produces results. The targets need to feel attainable but not easy, and you set short and intermediate targets to help stay motivated. It's not diet focused either. Obviously you adjust the targets based on the individual. If the person feels like they are not making good progress, it's an easy way to introduce questions about other aspects of their lifestyle, like diet and sleep quality - without being intrusive.