I've been looking forward to that video since it plopped, and was not disappointed!
Attaching the same tiny sample size caveat as in the video, the following are my thoughts:
Japan turned up and copied British bikes, then surpassed. I thought China would do that, and I expect eventually they will, but then bam, India jumped in. Or rather Royal Enfield did.
I did also wonder if Royal Enfields all being low stress low output engines helps. Bit of blutac in there? Never mind! But the rest have many bikes so we don't know. The BMW could have been a scumbag 800cc, or a lovely boxer :p. I suppose stats say it's more likely to be a GS ey.
Harley was as I expected. I assume that being recent it's a sample from their "hey we just realised how to make bikes!" new lineup.
Anyway I'm not buying a ducati. Unless it's reaaaally old.