Personality rather than occupation (or, badly developed villains)

Yesterday I was watching a couple of movies from my earlier life (they were animated) and at the end the moral was pretty clear. 

I. Hate. These. So. Much. 

Don't get me wrong, I adore movies with a good moral but I would rather have it not presented directly. Maybe the reason why I hate these flicks is because it somewhat limits people's creativity. Especially for those kids that need to work out things for themselves. 

For example, let us take a "good" character and have him/her a specific job or occupation. Scrap that, make him become an artist. (I have nothing against artists, I draw myself) and have the antagonist a scientist (I chose this because scientists are sometimes portrayed as evil). What message is this sending to little five year olds? That they should't be scientists? 

I understand that these characters have usually done something wrong but I can't see why these movies would show different occupations or body types as reasons why the person/character evolved to be bad. Why not allow the villain to become one because of an event, mentality, or personality? 

I hope I've written this clearly and that this only applies to certain villains. Not all.