I didn't read that essay the same way. I'd say he was making an observation rather than expressing a general concern.
He also said "Good" and "bad" technological progress aren't sharply differentiated, so you'd find you couldn't slow the latter without also slowing the former"
Of course he is expressing concern. Did you not read the second half of the essay? He's mostly talking about how people, including himself, have avoided, are avoiding or will avoid addictions.
He also said "Good" and "bad" technological progress aren't sharply differentiated, so you'd find you couldn't slow the latter without also slowing the former"