Words have meaning and power. This is something you don’t understand.
According to the dictionary, the word ‘kid’ has three meanings - all legitimate.
http://www.merriam-webster.com/dictionary/kid
And yes, one legitimate definition of “kid” is a ‘young person’.
According to the etymology of the word, ‘kid’ has been an acceptable way of referring to a ‘human child’ since at least the 1590’s.
So I choose not to change the entire English language because you’re offended by an ancient implication. (Which probably did start because a gang of rowdy children does resemble a herd of rambunctious baby goats.)
The day I do, I’ll stop referring to those in the Air Force as ‘airmen’ and start calling them ‘airpeople’. I’ll also stop calling my cat my ‘pet’ and call him my ‘non-human companion’. And my ‘husband’ can become my gender-neutral ‘partner’.