That was my takeaway from CS61A at Berkeley. I thought that Scheme was incredibly elegant and I was disappointed that we never used it again. The profs sure were pleased with themselves at the end of CS61A and I imagined later that they thought their preferred outcome would have been that we pursued a PhD using Jikes. SICP was the text which everyone bought and no one (that I knew) read and I tried. We had no assigned readings; it simply meant to be worshiped. It comes up on HN but never in conversation. No one quotes SICP.
I'll look at HTDP.