Maybe its similar to what happens sometimes with young deaf children whose parents are deaf? The parents sometimes refuse to get cochlear implants for the child that would give the child normal or near normal hearing, on the grounds that they want the child to grow up fully in "deaf culture".

Many who have been deaf all their lives, as opposed to those who lost their hearing as adults, view deafness as just a difference, not as a disability to be cured or fixed, apparently similar to the way most see race and ethnicity. Telling them they need to "fix" their child's hearing apparently to them is like, say, telling a Jewish family they need to raise their kids Christian.

Achondroplasia has a hereditary component, so there will be families where both parents have it and their child has it, and they have many relatives with it. I would not be surprised if some of them feel that there is an achondroplasia culture, and it is wrong to "fix" a child to make them fit non-achondroplasia culture.