I believe his complaint is that SI defined 1 Hz as 1/s, not as 2π/s. So 2π Hz in the new definition is 1 Hz in the older.
It does make the Hz unit a bit redundant (saying "hertz" is no faster than "per second", and tends to obscure rather than elucidate). Though I do believe it ultimately has saved confusion as it means the 2π multiplier must be explicit,, which prevents accidental confusion between cycles per second and rate of rotation.
Thank you, after reading the above, I went to the source, Alan Eliasen's units.txt.
You're right, there's a history of changing standards. Without having much familiarity with the topic, I'm inclined to agree that the unit of frequency based on cycles per second, in radians, is more consistent than a "radian as the dimensionless number 1" per second.
The base unit of frequency in the SI used to be "cycles per second".
This was fine and good. However, in 1960, the BIPM made the
change to make the fundamental unit of frequency to
be "Hz" which they defined as inverse seconds (without qualification.)
Then, in 1974, they changed the radian from its own base unit in the SI
to be a dimensionless number, which it indeed is (it's a length divided by
a length.) That change was correct and good in itself.
However, the definition of the Hz was not corrected at the same
time that the radian was changed. Thus, we have the conflicting SI
definition of the radian as the dimensionless number 1 (without
qualification) and Hz as 1/s. (Without qualification.)
This means that, if you follow the rules of the SI,
1 Hz = 1/s = 1 radian/s which is simply inconsistent and violates basic
ideas of sinusoidal motion, and is simply a stupid definition.
The entire rest of the world, up until that point, knew that 1 Hz needs to
be equal to 2 pi radians/s or be changed to mean cycles/second for
these to be reconcilable. If you use "Hz" to mean cycles/second, say,
in sinusoidal motion, as the world has done for a century, know that the SI
made all your calculations wrong. A couple of times, in different ways.
This gives the wonderful situation that the SI's Hz-vs-radian/s definitions
have meant completely different things in the timeperiods:
It does make the Hz unit a bit redundant (saying "hertz" is no faster than "per second", and tends to obscure rather than elucidate). Though I do believe it ultimately has saved confusion as it means the 2π multiplier must be explicit,, which prevents accidental confusion between cycles per second and rate of rotation.