At uni, if you pass, you pass. There's a saying, "P's get degrees", however, there is the addendum "... but HDs get jobs".
If you have any intention of going into higher study (honours, masters, phd), you'll need a strong average, usually a distinction or high distinction WAM and a high GPA. Given that these are based on your unit marks, you'll need to do well to make yourself mor employable and competitive in your chosen field.
Failing sometimes has immediate consequences as well as protracted ones. If you fail a unit, sometimes you will need to retake that unit, as it may be a prerequisite for other units. Even if it isn't, you may not be allowed to progress in a course without having passed said unit. Furthermore, if you fail a unit multiple times (I think it's more than twice) you will be brought up before an academic review board to explain. This board has the power to remove you from your course if they deem it necessary.
It's also a lot more fun and challenging to learn at uni, because its all on you. There isn't any of the high-school spoonfeeding at uni, where you have to do your own research and learn a lot under your own guidance.