It's not out of desperation, but out of admiration.
If he leaves so be it. But I prefer he stays and retires here.
Ronaldo is a player to admire, no doubt.
But I don't think it's wise for him to retire at Juventus with those salary demands. A player who's declining (not rapidly but he's still declining), will be 37 years old in little more than half a year and who's salary is eating the clubs budget up shouldn't be someone you extend with when you have to rebuild and try to start a new cyclus.
To give you an example: Lewandowski will be 33 in a few months and has a contract with Bayern until 2023. Do I wish for us to extend with him? No.
Lewa is a fitness freak like Ronaldo but I don't think we should aim to extend with him as long as his contract is still running a few years more and with his age being what it is - he will most certainly also not take a paycut.
It's difficult with players in that caliber because as you say, they're admirable and produce such great numbers. But you just gotta part ways at some point.
While Real Madrid suffered after they let go of Ronaldo was it in terms of long term planning probably the right choice. I felt Bayern clinged on to Robben and Ribery for too long as well, imo they shouldn't have stayed beyond 2017 - Robben maybe but Ribery certainly not.
Extending with Chiellini doesn't even affect your wage structure or the club but keeping Ronaldo beyond 2022 means you might not be able to sign the players you need in other positions because he eat so much of the budget, that could be the midfield that keeps being neglected. Just have that in mind.