Unfortunately, baby talk seems to have gotten a bad reputation, and this is why many people advise to avoid it. It should not be ditched, at least not the right kind of baby talk.

Baby talk is normal speech but higher in pitch and more sing-songy, with some dragged out vowels that make important words longer. It often has simpler sentences with important words at the end of the sentence – at least when children just start to understand and talk. All of these little modifications are perfect for the developing brain, and get the babies’ attention, while making language more accessible to learn. Here are related articles.