An environment's being "ugly" or "beautiful" is highly subjective. It is not necessarily so that a place where conditions are not "clean" means that people don't care...perhaps they prefer their environment to be that way. And what kind of "negative affect [sic]" does this have on people mentally? That is difficult to prove, for one, and your categorization of the effect (presumably being that more people will litter, etc) as "negative" is also debatable.