And yes, the distinction is pretty subtile and the perception of witnesses true role is complex as you stated.
I think the consensus is more about the perception of who is honest or not than about the witnesses. Witnesses units are just milestones (and assistants to validate previous transactions as fast as possible) in the path until the genesis unit which allows normal nodes to selected the best/main chain.
But, imo, you can't say "they are just milestones" when they are a key element. The referee of the match. The flow that makes transactions confirm and root them into reality. The path that all users follow to achieve finality of data they post.
Can you have a formal match without referee? No.
They are THE milestones.
Also I wanted to share another thing.
"well, we dont need to focus on tps because low usage...". But I see it differently:
Can be presented byteball to, for example, google, and ask them to be a witness, with a transaction platform which "only" achieves 15tps and clogs up at 20? NO.Can be a good advertising the real tps amount after improvements? YES YES definitely yes.These milestones are key elements for normal nodes due to their reputation of honesty and because they immune the network against some kinds of attacks. But pathes choose by normal nodes don't need to cross all the witnesses (majority is enough) and in fact they can be parallel until the main chain jonction. In worst case scenario, the jonction will occur only at the genesis unit.
It's hypothetical, and deserves Tony confirmation, but I think that it could be possible to have a formal match even without "referees" because the normal nodes will choose the best path, from their own point of view, until the genesis unit. Unfortunately, the path could be pretty long and could cross the path of bad players. That's why Tony introduced the witnesses concept as a shortcut until the genesis unit and to immune the network against attacks.
Well, TPS is a complex question. I don't think to be able to give you a good answer because I agree at same time with the previous answer and with your position. I can just hope to be myself working on an improvement ^_^;