Why I Carry My Son

As a parent of a child with special needs. I was expecting the stares, the avoidances and the reassuring.
Today, I was told “I would not be carrying him”. “He can walk.” “Oh my back.” They exclaimed.
Sure, the person meant well, but is it something that should be said? Sure, I explained my son has special needs (I kind of have to). But I could tell the person was still kind of eh.
I carry my son at the age of 4 to keep him safe. Sure, it hurts my back eventually. But my number one priority is to keep him safe. If I put him down he will run away faster then I can catch him.
If I try to make him hold my hand he will force himself away or drop to his legs to get away.
My son is a runner. So I carry him to keep him safe. Sure, at times he rides in a cart or stroller. But in this situation it was easier to just carry him.