I don't know where the "80%" comes from, for some assessments then 50% is a pass, others you might need 100%. The rationale for the latter is self-evident - if you were teaching someone to tighten jesus nuts on helicopters etc.
Studylink is student loans - not fees-free study. More info can be founds on the feesfree.govt.nz site.
But you're right about the 80%, not every course has % grading, and if they do 80% is a pretty high threshold. I think a pass would be sufficient, as this policy is aimed at the less academically minded.
Yes I know that's about student loans - that was actually what the OP asked about. :-)
LOL. apologies, i fell victim of reading what I wanted to see, not what was written. I assumed it was about fees-free policy