Norvig actually did comment on this publicly once on the Lex Friedman podcast. Basically what he said was that lisp ended up not working well for larger software projects with 5 or more people on them, and the reason why they never used lisp in any of their books again was because students didn't like lisp. Norvig doesn't seem to get why students didn't like lisp, and neither do I but somehow this is the real reason why it was abandoned.