I don't like kids. I'm not old and crotchety by any stretch but I do not like children on principle. That is to say, I don't act particularly surly towards youngsters in the street. The negative feelings I have for <18 year olds is in theoretical terms, mostly. It isn't that they are "loud and obnoxious". I often say that I'm a child at heart and I prefer to be silly more often than not. Playing often gets noisy and I don't mind that. As for 'obnoxious', teenagers win out over children in that department.
Firstly: A lack of discipline. Now, I don't mean to say a military-like discipline where a kid doesn't speak unless spoken to. I don't appreciate the meant-to-be-seen-but-not-heard mentality. Stifling a child negatively affects their development. I am referring to an ignorance of how to act and when certain behaviour becomes inappropriate. Crying and temper tantrums come to mind before 'cute' and 'adorable' when I think of children.
Secondly: I find their sense of humor and wit wanting. Ok, ok, I know I can't really blame them for this and I don't. Nevertheless, I don't care for it. I have a deep-seated love of scintillating dialogue and bandying of crooked words.
When the childrens annoy me I picture this scene:
And you'd better believe I loved the mid-credit scene from Step Brothers. (^_______^)