Lots of of sport trainers are starting to see the light. Thai boxers traditionally ran themselves to death. Most of the top coaches and athletes are cutting back on that in favor of resistance training. Of course cardio is a pillar of fitness it's just many athletes neglect the other pillars.

Walking is considered separate from anything with kettlebells mentions by Parent, right?

Not sure if they meant farmer carry type walks with the kettlebells - regardless all are good activities

Why would you consider it a meme? I thought that's the general consensus in recent literature.