If that's what you believe to be a topic of discussion within the scope and context of the article, that's your perception. Readers can decide that for themselves.
Read the article and tell me whether you perceive the topic of discussion regarding levels is their precision or how they are distributed and let me know.
How does precision become the topic of a discussion without ever mentioning the word precision at least once?
He was complaining that there was limited quantizing density in the midtones and shadows because of the use of a linear ADC. Never mind that that is a red herring because of noise, but that's one of his points, and a reason he advances for ETTR. ETTR is a good thing, but that's not the reason.
If you think that 64 bits is not sufficiently dense quantization for some shadow level, but want to stick with linear ADCs, then the obvious solution is to increase the precision of the ADC. That's what many people who bought Bruce's bogus quantization density argument clamored for, and one of the reasons we ended up with silly levels of precision in some Hasselblads, which ended up allowing them to more finely digitize pure noise.
The thrust of his argument about quantizing levels points towards a solution that doesn't work.
Another clear sign that he was confused was his talking about shadow posterization arising from a 12-bit ADC. The CCD sensors of the era had so much noise that that wasn't going to happen.
"Film mimics the eye’s response to light, which is highly nonlinear. Most of our human
senses display a significant compressive nonlinearity—a built-in compression that lets
us function in a wide range of situations without driving our sensory mechanisms into
overload"
It is not, in general, true.
Slide film has a expansive, not a compressive, nonlinerity.
Negative film developed to N has a compressive nonlinearity.
Negative film developed to N+x can have an expansive nonlinearity.
Negative film optically printed on paper is approximately linear when you get away from the toe and shoulder regions.
"Note that the on-camera histogram shows the histogram of the in-camera conversion to JPEG: a
raw histogram would be a rather strange-looking beast, with all the data clumped at the shadow
end..."
That's not true at all, as a few minutes spent with RawDigger will demonstrate. There's no reason why a raw histogram has to use a linear x-axis, and for many purposes, it's better to use a nonlinear one.