Might have been Waterloo's Introduction to Functional Programming (CS 135). I have TA'd (technically ISA'd) that course several times and helped countless students in office hours. The struggling students didn't just hate Racket, they hated the whole HTDP philosophy of following a "design recipe" and writing documentation prior to implementing a function. Most of those struggling students essentially waited till the last minute to do the documentation, completely flouting the intention of the course.

I don't know if the strong students had the intended approach since they were never in office hours asking for help!