No, he set out the needs for RF then compared it to audio to make his
point.

But what point is that exactly? He's comparing apples and oranges. Or
rather, contrasting apples and oranges.

Audio is not as high frequency as RF so don't use CATV coax

There's nothing wrong with coax. Many people use coax for their preamp
signal cables. The input impedance of amplifiers and processors are
high enough to make any effects of increased capacitance negligible.
I've yet to see a practical application where it can be used for speaker
wiring - where capacitance can actually be relevant.

and
since the wavelengths are so long, don't worry too much about cable
properties having a majore impact on the system. We run cabling in such
short lenghts that it really doesn't matter. I read the link you posted
and he summed it up the same way.

Yes, transmission line theory can be neglected in car audio. I don't
know of anyone using any elements of microwave theory to support using
different kinds of wire in car audio though, so I don't know why the
author insisted on addressing this.

"12 AWG seems more than adequate, even for demanding systems, high power
Speaker levels, and reasonable lengths.
The effects of 3.1-m cables are subtle, so many situations may not
warrant the use of special cables. Low-inductance cables will provide
the best performance when driving reactive loads, especially with
amplifiers having low damping factor, and when flat response is
critical, when long cable lengths are required, or when perfection is
sought. Though not as linear as flat cables, 12 AWG wire works well and
exceeds the high frequency performance of other two-conductor cables
tested."

How did the author come to these conclusions? None of what he said
prior to this statement was relevant to it. He said little about the
reactance of the cable and its effect on the output.

Remember, he's writing in the context of home audio which some customers
are very demanding of and even go to such lenghts as building listening
rooms desinged around Cardas' principle among others. A very quiet
listening environment, unlike car audio. And, home audio speakers aren't
pressed into car doors, rear shelves, etc. They reveal a whole lot more
that even the best car audio set up can deliver due to acoustics. Room
interaction is a major player when it comes to great sound.

I realize this, which makes me wonder even further why he addressed the
issue like he did. Yes, home users are demanding. So what does this
have to do with telling people about the differences between two cables?

If I were to explain the differences, it would be as Fred Davis did: an
impedance explanation of attenuation. That is, how a voltage drop
occurs, and then compare the relative magnitudes based on the electrical
properties of the cable. The author you posted did not do this, but
instead talked about transmission line theory. Since virtually no one
was citing transmission line theory as a reason for using one cable over
another, I find that it was completely unnecessary to do so. Therefore,
it hardly serves as a comprehensive explanation of why cables are
different, and more importantly, what the relative magnitude of these
differences are.

I don't mean to criticize your posting this on here, because I think
it's an interesting analysis probably worth reading by anyone who wants
to know one of the differences between the requirements for transmission
of a very high frequency and very low frequency signal (though a bit
misleading in a couple other areas). However, I just wanted to point
out that it's not an explanation of what the differences between cables
are and how such differences may or may not be significant.