I often refer to young children as short people. Well, they are. And I confess that I am not always fond of them.
I've given the subject a fair amount of thought over the years, actually, and generally the antipathy comes down to two issues. One, they're often covered in unpleasant and sticky substances. This ick factor is, obviously, easily solved and not always the child's fault.
But two, they often add being ill-mannered to the sin of being a bit dull, and that is far less easily remedied and, frankly, far more annoying (and this from someone with quite a low tolerance for ick). Parents who allow their children to run wild, to utter shrill shrieks when there is no blood gushing, to interrupt adult conversations when there is no emergency and without politely attempting to gain attention first, and who otherwise abdicate any responsibility for instilling self-control and a sense of appropriate behavior, are not doing their children any favors. It's a harsh world; people who grow up without being able to exercise self-control and adapt to subtle social cues will likely suffer the consequences.
I quite like snuggly infants, and I don't mind teenagers (as a rule) and sometimes quite like them too. It's all that time in between that can be difficult.
Of course I don't endorse being mean to children, or humiliating them for amusement. Such tactics are ineffective--and morally reprehensible. I simply think that one should treat children more or less as one does a good dog: firmly, consistently, and with lots of love and baths. The difference is that one must explain situations to a child, so that the child can learn and apply such lessons. A dog's language and reasoning capacities don't seem to be quite up to that level.