This is not even remotely common sense. E.g. why can this allergy be desensitized via ingestion but not via skin contact?
Hindsight is 20/20. In this case, it was figured out after a lot of scientific research.
Just because we can understand it now doesn't mean it's "common sense". It's very much the opposite, and you discredit the scientific research this has required.
Where I come from this was a widely held belief by the end of the 2000's: If you raise a child in an overly sterile environment and/or feed them a very limited diet, they are much more likely to develop a bad immune system and allergies. It was also believed that this idea came from science, but I guess not?
Here's an early preview for the next bombshell of this area. Breastfeeding is extremely beneficial. "Infant formula" should not be the main thing a baby is consuming.
To me it discredits science a lot more when things like this are treated as arcane or brand new knowledge. It's good when we can lock in reasoned beliefs as definite fact, instead of just reasoning which is often incomplete or flat out wrong. But when it's right and people act like this about it, it just makes it look like "scientists" know less about the world than my grandma, and that my grandma would make better calls on national health policy than the people currently in charge. Obviously that's not the case but I wouldn't be unjustified in thinking that during times like this.
It is important to memorialize and standardize "common knowledge", as without memorialization, knowledge drift can cause a loss of the "commonality" intrinsic to the knowledge.
This is not even remotely common sense. E.g. why can this allergy be desensitized via ingestion but not via skin contact?
Hindsight is 20/20. In this case, it was figured out after a lot of scientific research.
Just because we can understand it now doesn't mean it's "common sense". It's very much the opposite, and you discredit the scientific research this has required.