> Students do not like Racket

That is kind of the killer, isn't it? 10+ years of Racket and students still hate it. If they can learn introductory CS without suffering through Racket, why force them to do so? (Disclaimer: I think Racket looks interesting but I have never tried to use it for a project.)

But why not allow students to vote with their feet? Offer Racket and Python and see which course's graduates do better in the rest of the major.