I didn't want my 4 year old unnecessarily traumatized. He was frequently sick and had to see doctors regularly. He had enough baggage over that, and was later diagnosed with a genetic disorder.

I knew what I was doing. If a parent doesn't know, sure, get the IV. But if a parent does know and wishes to spare their child some pain, I see no reason that should not be supported. The comfort of my children mattered to me. I cannot imagine that it wouldn't matter to most other parents.