Out of curiosity, which US university did you attend? I went to a well-known and highly-regarded public university in California, and they absolutely did not coddle their students. Poor-performing students regularly washed out.
Perhaps you also don't have a comprehensive picture as to what is available to students across every university in Europe. Europe, like America, is a big place and, like America, the situation probably varies by institution. As with most things, the answer is probably more nuanced than general observations would make it seem.