We choose not to. Just because it is in the name of public health, it does not make it good. In Australia it is illegal to ride without a helmet - be it on a horse, bicycle or motorbike. It is also compulsory for occupants of a car to wear seat belts - both in the front and back seats. Childproof fences have also been made compulsory around swimming pools.
Medicines come in childproof containers and cigarette lighters have childproof locks.
These are now accepted. They are not controversial. You are a crank if you question their wisdom. They were all introduced in the last twenty years amid some debate. They were all perceived to infringe freedom.