It seems reasonably clear that the ongoing cost in terms of anxiety and, to some extent, the freedom to change or loosen up things is simply not worth the accolade to him anymore. The article states: "because of the huge pressure of being judged on every dish he serves... and the anxiety over Michelin’s anonymous food judges, who could arrive at his restaurant at any moment... “You’re inspected two or three times a year, you never know when. Every meal that goes out could be inspected. That means that, every day, one of the 500 meals that leaves the kitchen could be judged. “Maybe I will be less famous but I accept that,” he said, adding that he would continue to cook excellent local produce “without wondering whether my creations will appeal to Michelin’s inspectors”."
So, he's quitting on his own terms. Assuming it's not a rash decision borne from burn-out or some temporary phase or state of mind then I think it's admirable.
A do understand how receiving a Michelin star can bring in different clientele that changes the atmosphere of the restaurant for the worse.
You cannot allow yourself to not be perfect. For example, you cannot serve something new where you know it is really good but fails a bit on the texture side or it is hard to produce so the quality varies a bit, not a lot, but a bit.
If he goes out of the system, he can reintroduce this little bit of freedom.
As a programming analogy, 3 stars is like every single piece of code you produce is perfectly structured, integrates nicely in the software, respects the conventions and idioms, has no code debt. You cannot just patch a bit and see how the users react and refactor later. It must be perfect for the user from low level code to the interaction as soon as you put it in the hands of real users.
I am full of respect for such decision.
I'm reminded of Ron Blaauw, a Dutch 2-star chef who was also tired of the pressure of his 2-star fine-dining restaurant (not sure if it was Michelin or just the kind of restaurant), so he started his more informal "Gastrobar" for just a quick bite instead of Michelin-level dining, and was immediately awarded a star for it.