We have for a long while made the argument that he makes at the start. Gist on arguments on SF has been:interesting take on "don't count" here, I wonder if that science holds up? good ad for his course at any rate
Counting distracts brain/concentration from being able to listen to the rhythm and ability to then dance or step to the rhythm. One of the two - rhythm or counting has to be in the background. If you are counting your brain gets focused on keeping the count consistent (not same as keeping the stepping to the count consistent).
If you get used to stepping to the count it is same as stepping to the metronome. Then when you have to react to the rhythm in the music, you have got too used to stepping to the count rather than expressing the rhythm with your steps. Not to mentioning dancing ahead of the beat or behind the beat. Which is whole another discussion we have had.
To best I know there is no scientific studies to back this up. Perhaps it would be an interesting study. But having seen may dancers in salsa where counting is a gospel and non salsa dances where counting is used as an aid to explain but not dogmatically passed on to students as in salsa - it strongly suggests starting off by concentrating on counts (metronome) rather than rhythm produces deficient dancers. They can step. But they can’t dance. Hence lack of musicality.