This proof doesn't show that Kolmogorov complexity of any fixed string is 0, it shows that Kolmogorov complexity of any fixed string is constant (which is trivial). That is obscured by an abuse of notation which makes arguments about Kolmogorov complexity easier to parse in 99% of cases. So, imho, this post isn't very substantial - it's essentially a garden variety "1 = 2" sort of argument.