Having attended both types of college, I actually had the opposite experience. At the community college, I was taught entry level classes by PHds who taught purely for enjoyment. The students were largely very motivated and professional. The university I attended was decent (top 60s), but all my direct interactions were with graduate TAs, many of whom struggled with the English language. The students mostly just wanted to party and constantly needed their hands held.

Most likely I just got lucky. My main point is that anecdata isn't very good data.