Curricula are standardized. All students experienced almost the exact same disconnect. This is also not some secret, all Professors know this and some try their hardest to bridge the gap.
Then this is a failure of the system in Germany, and does not reflect the experience of many American kids. Some, yes, but not all. Primarily, it's the "smart" kids who didn't have to work for good high school grades who have a bad time in university, not the kids in the fat part of the curve who more likely matriculated having already developed strong study skills. In my experience, at least, the biggest difference between high school and college is that high school teachers teach and homework is for reinforcement, whereas college professors expect self-learning to be the core method of pedagogy and their role is to reinforce and contextualize the topics. Switching from one mode to the other can be rough, no matter how innately intelligent a student is.
Maybe aligned/frameworked/pooled but no full uniform testing or single curriculum across all the states in Germany, for example - so variations exist and some schools might prepare better than others.
