Unis are generally more organised than tafe. They also tend to have people that are more academically inclined for subjects like IT where it's necessary. Generally the level of education of a uni for 'academic' subjects is better and that's why most people will do like a diploma at TAFE and then apply for uni if they didn't get in initially.
Source: I have a friend studying IT at tafe and he tells me how unorganized they are. Like once I think they literally forgot to give out some assignments and ended up giving everyone the answers.