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I suspect because first, it's very humbling. I have tried it and just don't have the flexibility, wrist strength or core strength to even do more than an empty 20kg bar.

Second, the way that fitness has been introduced to the most people in the last 20th and early 21st century has been through fitness classes. Either Jane Fondas and Mr. Motivators on video or in person with classes like Les Mills. Those classes could never include an exercise like that because they couldn't coach a group of 40 people to do it safely

could it also be because it seems to be that it could be very damaging to one's back?

That's what I meant with my last statement above. I think that if you have the strength and mobility, then no exercise is 'bad', but it's unlikely that most people in the modern day have the strength or flexibility to perform this movement safely!