Earlier quoted context omitted.
I guess it really depends on the student's motivation (and age, most likely). My experience was that the biggest danger is not them learning the 'wrong' things but giving up in frustration a few weeks/months in after not getting anywhere. So it's paramount to get them on something that can achieve their goal (or something close to it) ASAP, so they get hooked on making cool stuff before getting frustrated and droppin…
From the article linked upthread: “[Ryan] reacted very positively to the initial ‘intro to racket with pictures’,” Carmack wrote, “which was a contributing factor to settling on Racket. Java / C# work seemed to feel more like homework, but changing numbers and colors in the REPL had him smiling and excited.“ So Racket does seem to offer that kind of quick feedback.
Anyway, to each their own!