I have to say that the video itself is bologna. I've sharpened a wusthof ikon to 10K+ and the performance is far superior, especially compared to what I see in the video for the coarse grit edge, and also that is the only way to get such a knife slicing paper thin. Whatever this individual did to "polish", the fact is he did not produce a keen edge.
The large carbide size of cheap stainless practically guarantees you a toothy edge, even at high grits. One explanation for what we see in the video, aside from poor sharpening technique, is that he wound up putting on a rather obtuse edge, in which case I don't think he'd actually be cutting hair very well, and of course he did not demonstrate any hair shaving.
There is a lot of debate about what holds up better here, a coarse or fine grit edge, and possibly both sides are right. I suppose it has a lot to do with a number of factors, particularly sharpening angle, the things you cut, and the way you cut them.
All I can say is that for my own experience with cheap stainless [using acute angles, light to no board contact], a polished edge works better all around.
Actually, I did do a bit of board work with the Ikon at one point. I thought it held up rather nicely to the pounding with the high-polish microbevel, but boy did I have a lot more fatigued metal to remove come full-scale sharpening time, which of course would be expected.