In fairness to Hal Abelson, the pontification I remember isn't in the lecture in question, and my annoyance is more directed at pretentious classmates and some other things edit and aimed at marketing style, rather than substance.

If I were to attempt to summarize the lecture in question, it would be "The Greeks named Geometry after measuring the earth, but hundreds of years later think of them as wrestling with more fundamental ideas about space. Hundreds of years from now, people won't think of computer science as writing C programs for silicon, so much as wrestling with more fundamental ideas about <X>".

If you think that I'm missing the important crux, please let me know

It's a profoundish idea, and an interesting one to think about.

But (my point) I don't think it is an important misconception for the general public that computer science is about computers when it is in fact about <X>. For 98% percent of humanity, and a good portion of computer scientists, Computer Science is a good name.

If DNA computers were big, or nanoparticle cellular automata building large structures were a thing, I would be more for separating out computers and <X> to the general public. I hear the meme more in circumstances I interpret as trying to sounding counterintuitive and deep, which I think is the cause of my knee-jerk negative reaction.

EDIT The people I am quoting do not live in my world. They are at places like the Center for Bits and Atoms, where they really are studying the <X> without the computers. But for the masses, today, in 2015, I do not think the distinction matters.