I think that is actually his point. If you don't have to turn your head to the side to look back, at your speed, etc., the road ahead stays at least in your peripheral vision, at most an eye movement away.

I mean, have you seen how some people fiddle with their radios while driving? Personally, I'd be happy if at least a part of those people had the chance to keep their eyes on front while they do that. I might be biased though, due to the german speed limits and not being a driver myself :)

What about checking your blindspots? My 2005 subaru outback has terrible visibility when trying to look back and left (the posts somehow block most of the view). On highway merges, my spouse helps check the blindspot for me or I ask her to look ahead while i crane my neck around.

There's also some nice-to-have information on the dashboard, which is why the dashboard is placed where the driver can easily see it.

Having your speedometer on a HUD instead of a dashboard does not make someone incapable of paying attention to the road.

Wouldn't a HUD be less of an obstruction to your field of vision rather than multiple controls and readings spread throughout your dashboard?