The brain itself is the opposite of neoteny for humans, it is more developed than in other apes.
Also have you considered there is NO selective pressure for baldness? Without selective pressure there is NO evolution. Women do not like baldness, there is no increased reproductive rate in bald men, at best it's equal with men who do not go bald. It's probably a little lower. Therefore baldness does not fit the most important criteria for evolution, being something that builds up in the gene pool over time due to selective pressure.
Not true. First of all, neoteny applies to the womb and early infancy. It's a fact that human babies' brains are much larger in proportion to the rest of their anatomy, than should normally be the case with adults(that's why humans have more problems giving birth). Secondly, there may well be an overall evolutionary advantage re losing body hair from all over(otherwise why did we lose the fur-like hair our apemen ancestors had?). It's just that baldness hasn't fully evolved yet as a trait, only partially, perhaps as the end of a long run of evolution causing hair-loss in the rest of the body.
Also, women do not necessarily discriminate against baldness. Indeed, various studies re this have shown that women find bald men more intelligent. Another point is that while baldness(or less hair in general) may be a positive trait, the fact that baldness is also a characteristic of older people in particular, might put off women, so that the evolutionary bonuses and negatives of being bald cancel each other out.
Another point made by scientists is that evolution has stopped, for all intents and purposes, as we are no longer subject to natural selection, so that we can't strictly speaking, tell how much balder(or less bald) we would be in the future.