The angle of attack of the pulling force aside:

Isn't it funny how the other anchors start out in hard sand? You can
see large parts falling off while the anchors are high speed dragged;
that sand looks hard enough to drive on.
The rocna starts out in a muddy pool of 'quicksand' that is so soft
that even the pieces of mud/sand that the rocna piles up melt back into
the surface immediately. Watch the left foot of the guy who tries to
work it free after the test sink in. And the rocna gets a nice slow
motion pull.

All that doesn't necessarily make it a bad anchor, but this video shows
a seriously bad test. The test proves two things we already knew: The
most important factor in anchoring is the substrate, and good marketing
requires artful lying. This was too blunt, mate, try again!