Wow I hope we never work together. A mature team trusts one another and assumes the best. If I got that feedback from a manager in a one-on-one I would put in notice that day. What a horrible attitude to bring to your work interactions.
However, I can also see that my expectations are not shared by you, based on your strong response. My gut tells me this is related to different communication norms with "digital natives." I think your assumptions of malice and inability to learn on the part of the manager are misplaced.
I'll allow that some of it may be generational; many of my younger colleagues have never called in to a conference call.
But I challenge your claim that I'm assuming bad faith. At no point did I question the motives of the OP, only their actions.
Edit: I should clarify, because my original comment could reasonably be read as assuming details about the internal motivations of the OP. Allow me to rephrase: if a mangers' default response to an individual not having a camera on is to dress down the person for not "being present", that manager is making a toxic workplace environment.
Your preference seems... clear enough to me? given that you said you would quit that day. What am I misunderstanding?
I believe your response of leaving rather than attempting to reconcile the difference in expectations is an indication of assumption of bad faith. As in, you seem to believe the manager would not be responsive to a discussion.
Growing up pre-internet blessed me with the ability to communicate effectively without body language, thanks to the telephone. I find that translates perfectly well to video-less conference calls.
> most of the time when people are video muting it's because they are hiding their distraction and lack of attention
The OP assumes that those who have their camera off are wasting time, because they can't see them to prove that they're not.
A meeting is specifically about communication. A participant at the meeting that is inattentive is either wasting others' time, or should probably politely step out, or at least should not have been asked to attend. Being present is a priority for a good meeting, hence the pejorative "butts in seats" comment doesn't make sense to me.