IIRC, MIT moved away from SICP, and therefore Scheme, because (something like) they saw the field for MIT EECS graduates changing -- from understanding how systems worked in detail, and being able to build from scratch, to assembling systems from off-the-shelf components. And I guess some thought that a currently popular language (first Java, and then Python) was more appealing for that.

One of the other objections to SICP, at least outside of MIT, was that it was too hard (especially for high school students). Which is part of why HtDP, and much of Racket supported that and other educational initiatives by Matthias Felleisen, et al. https://htdp.org/

I'm curious: Did MIT use Racket at some point for SICP, rather than MIT Scheme, either officially or grassroots? Jens Axel Soegaard, Mike Sperber, and I made some conveniences for doing SICP with Racket, circa 2009, but I don't recall hearing that Racket was used for SICP at MIT itself, only at various other places. https://www.neilvandyke.org/racket/sicp/