43Today - I agree and disagree with your points!
I never actually said you shouldn't run. I think my post actually said, "It is a good addition but not the key" ie running by itself is not the only way to lose fat.
If you're not changing your diet, or eating healthily you won't get much change.
Also, you have to look at running on your joints. Reports state that each running step places over 3 times your bodyweight on your hips and knee joints. If you are overweight this can be some load. Therefore running can be causing extra stress to the body, maybe not short term, but certainly long term.
Your client who lost the weight, without 'dieting', must have been consuming good calories. I don't like the word dieting. But eating healthily (whole, natural foods, not processed, packaged etc) supplies the body with nutriton it can deal with.
All of the health benefits you stated with running can also be achieve with resistance work. Try some interval training with weights or bodyweight exercises. On that subject resistance work doesn't have to be 'gym based' How about pressups, squats, lunges, mountain climbers, burpees, dips, plank etc, all using your body weight and still resistance training.
Running too much or too long, actually puts the body into a catabolic state, which results in muscle atrophy, or wastage. Surely this is not what we want? Especially as muscle gives the body shape, and good posture, and acts as an additional living tissue, burning calories even at rest.
I train my client at my home gym, so if they can afford a PT, they can afford a gym membership, but even if not, they can still exercise at home with bodyweight exercises.
I agree with your last paragraph!