PTX is not the IL used by Nvidia's drivers, but does compile directly to it with less slop involved. If you had said "PTX's instructions are analogous to writing assembly for CPUs or any other GPUs (ala Clang's AMDGPU target)", that would have probably been the better way.
Arguably, PTX is closer to being the SPIR-V part of their stack (more than just an assembler compiler, but similar in concept). None of Nvidia's tools really ever line up with good analogies with the outside world, the curse of Nvidia's NIH syndrome.
Generally, you're not going to be writing all of your code in PTX, but I find it wild you think people going to "an average technical university" would be unable to use it for the parts they need it for. That says more about you than it does them.
All of Nvidia's docs for this are online, it isn't that hard. Have you tried?
How else would you have understood it? At this level it's literally just pedantics. In the same way you can say C doesn't technically compile to assembly for CPUs. The point is that it's the lower abstraction level that is still (more or less) human readable. But just like in CUDA, you may want to write parts of your code in it if you want to benefit from things that the higher level language doesn't expose. The terminology might seem different, but in practice it is pretty analogous.
With PTX, you are not writing in the native assembly of the Nvidia GPU, but yet another abstraction, just one more similar in nature.