Do you have any links to back that up?
I'm not studying at TUM but I'd be really surprised if there's a 80% pass rate for those subjects.
What is considered a passing grade at one of these schools?
At my private liberal arts college in the US it was usually (but ultimately up to professor discretion):
00-59% - Fail (0.0 for GPA)
60-67% - D (1.0)
68-69% - D+ (1.3)
70-72% - C- (1.7)
73-77% - C (2.0)
78-79% - C+ (2.3)
80-82% - B- (2.7)
83-87% - B (3.0)
88-89% - B+ (3.3)
90-92% - A- (3.7)
93+ - A (4.0)
You could count any class with a D or better toward graduation, but to actually graduate you needed a 2.0 or better GPA. If you did not have it you could take additional courses to bring your GPA up, but adding on 3-credit courses when you've got 120 credits built up with a sub-2.0 GPA is typically a losing proposition. Most transferred if they were sub-2.0 by the end of their Sophomore year.I've seen other grading scales with E's in addition to/instead of F, or minor variations on the percentages. It seems popular to give Honors courses an extra point (e.g. an A- is 4.7 instead of 3.7), particularly in US High Schools.
See https://en.wikipedia.org/wiki/Academic_grading_in_Germany
FWIW I did my masters there and in my opinion the way they evaluate students is suboptimal anyway - but I don't know if that's a TUM thing or a German thing.
yeah, my uni was pretty bad, all the useful stuff I learned and use daily came from my own learning, none from university. campus was a fun place and great experience though :)