No interns make that high of a salary. That means they value his work/skill. It’s clearly a management problem but this is a hard problem. In fact it’s different for everyone. Some people like well structured management and others don’t. On top of that he was remote, which makes it even harder.
His rants are mostly in sales. Engineer ranting about sales is like Sales people saying Engineers are pointless. (Btw both are very common perception). Now that I’ve done both ends I can share that sales people are doing that for a reason. At the end of the day, high end sales are all politics and you need to be good at the game.
This type of rant is what interns do.
This is a focus problem. Everyone have a different way of solving this. For me, the best way is to write what I want to achieve on paper and start doing it right away. I don’t do anything else until I cross out all of them.