Because his opinion is supported by the status quo (crappy cameras everywhere).
My anecdata says the same. In most video confs your video is put up on maybe 1/16th of the screen, to the corner, and people generally share something like a presentation. I guess if you're in sales, it matters more since your face will be fullscreen.
But even then... most people don't work in shiny offices anymore, are you sure you want to display your dirty socks on the shelf in the back in all their 8k glory? :-D
Camera aside - people will do wonders for their video presence by putting some effort into their background and lighting. If you’re not going to use a blur or picture background, clean up the area, consider how it functions as a backdrop (including wash lighting, etc), and what impression it’s making. Lighting is king - be deliberate about it.
I'm speaking more broadly about the world outside of hn - which is the world that actually matters - contrary to the imaginings of hn.