What is with all of the fearmongering on this app?

I've seen posts where someone is certain their young toddler must have autism because he's "very active". Another post where a baby has a very mild fever and people are saying she needs to take him/her to the ER for a complete (blood) work up. And others where people are encouraging fear if the OP shares that she needs help because her child has some cold/allergy symptoms (no fever, just sniffles and cough).

Whatever happened to people realizing that a toddler being active is normal, that elevated temperatures and colds, sniffles happen? What happened to people saying, "Hey, if you're really concerned call your baby/child's doctor. But there's no need to freak out, right now. Keep an eye on things and proceed accordingly."?

Why are so many people seeming to seek diagnoses or illness? And why this push to encourage fear?