I would wager that Sussman is being friendly and diplomatic towards his department here. I think the move away from SICP was primarily due to Sussman and Abelso

I would wager that Sussman is being friendly and diplomatic towards his department here. I think the move away from SICP was primarily due to Sussman and Abelson tiring of teaching the course, which I believe Sussman says here or in another talk, changing tides in the landscape of universities and their relation to the job market, and a departmental political move. The move to Python was probably as much of a marketing choice and personal choice based upon leadership in the department than anything. There's an MIT professor, John Guttag, that wrote the Python book that they use and that's used in MIT's MITx and edX courses. I doubt he just wrote it and then the department just happened to later switch to Python and adopt the book. I think Sussman's answer is more of an observation of the result of the switch and not an explanation why. MIT is a slave to fundraising, and I suspect the industry trends of programming languages, funding sources, job market, and other marketing and political decisions led to the change over anything actually technical.