Opinion only here: I think this is great for general health and fitness, and probably for your hobby jogger/runner. Heck, maybe for most of us, but not for elite runners. Sure elites need HIT, but they also need 85-100+ mpw if they are 5k and above.
For me, though....at 57, my real running days are far behind me. I walk a lot, I jog a little, and I do HIT workouts once or twice a week - nothing compared my youth. Something like 8x200 or 10x100 or 4x400 - with running times most would not even consider to be high intensity.
I personally feel that HIT and a few 20 minute jogs and lots of walking is far better for my health than to still be putting in 50-70 mpw.
However, I'm never going to toe the line again.