A 30% or worse failure rate seems high.
However the success of a teacher at every level is reflected in the successes of their students.
In some American universities, courses are deliberately designed to have a high attrition rate. They are called "Weed Out" classes.
Consider it like a sort of boot camp for university students. They are difficult-but-introductory classes, taken in the large-lecture format, which tend to thin out the herd a little bit. Of course, if you fail the first time you can re-take; most people if they don't pass the first time end up passing the second time.
Depending on the department it could be any number of things. They're often things that do require quite a bit of memorization (i.e. Anatomy and Physiology for pre-medical students), but can also be things that require quite a bit of multi-step or lateral thinking. In engineering it can usually be Physics I and Multi-Variable Calculus; but depending on the institution, it could be the Freshman Seminar (At my undergrad it was coded as ENGR101, a required course). Technically the latter isn't really a weed-out as most people pass, but there was a lot of busy work and essay writing for that.
For religion studies majors, I'm told that learning Greek and Hebrew can be quite taxing for the uninitiated.
Here's the kicker: funding does in large part depend on keeping students in the program, paying fees. Also, the prestige of our program depends on sending out competent graduates.
We are NOT intentionally trying to screw people over, but by the nature of things it is bound to happen.
If there is material that you absolutely must know before you go on to the real world, I have to try and make sure that you know it. Yes, some people do get screwed in the process - but they might actually find the major isn't really for them and go on to try something they actually like.