Because it’s not misinformation - the body absolutely needs glucose homeostasis to survive - if you don’t eat carbs it will make it out of protein. The body has numerous mechanisms and basically dedicated organs for the conversion, metabolism, storage, and production of glucose. The whole Krebs cycle is built around the processing of byproducts of glucose - so you’re utterly full of shit that it’s “only safe in a tight band”. That the body can additionally use fatty acids in the form of ketone bodies as a stopgap is a testament to adaptability - but even people on keto require a homeostasis of a close to normal level of blood glucose. And how do they get this? Through the metabolism of proteins which can be amazingly converted to the glucose the body needs to survive.
This is high school level biology, and easily reviewed with 10 minutes on Wikipedia.