Of course people are focused on it.
If someone wants to communicate a particular point, it's wise for them to eliminate the rabbit trails and distractions from what they say. It's especially distracting to the programmer-type if the side point is badly argued.
Human nature is, alas, fairly predictable in the large.
If you actually listen to (or read) what he said, he explains it quite well:
“Emacs is supposed to defend your freedom. It's supposed to help you to defend your freedom, and lead you to defend your freedom, which means it shouldn't lead you to throw your freedom away as soon as you visit a site that tries to send you a non-free program to run straight off of that other machine. So it's important not to lead users to do computing this way.”
I.e. if Emacs were to run JavaScript, people would use Emacs as a web browser, which would make Emacs help users run various privacy-invading JavaScript software.
I don't know why I care what he thinks so much, I don't even use Emacs. I just bristle at his dumb moral reasoning behind what should be as simple as, "we want to focus on things other than JS support, and we also want lisp to be the primary language interface, according to our vision". His whole argument here is just moral and ethical grandstanding.
I don’t think it is a moral or ethical question. The more freedoms you give away to companies with significant market power, the worse off you are in an economic sense.
See Microsoft’s takeover of open-source .NET libraries and VS Code extensions, the Intel Management Engine, the glued in batteries in Apple devices, Google’s efforts to make alternative OSs harder to run on Android devices and ChromeBooks which in their factory form are built to track you, Toyota’s subscription model to keep your remote key fob functional, Mercedes’ subscription model for acceleration, and so on.
You buy hardware, you use (and often buy) software, and they are more and more locked down so you don’t truly own them and are more and more designed to force you to pay more of your money.