That's well put, though it's not exactly how I would frame the origins and development of critical theory. Since Marx viewed his work as scientific, and this was, in his mind, what differentiated his work on understanding history and society, that takes these problems out of the hands of philosophers and puts them into the hands of "scientists." But the "scientists" who took up this Marxist project weren't scientists in the traditional sense, but more like you quote Marcuse as saying—scientists aligned with an essentially different order of truth. If we call this milieu critical theory, which is apt, and we disregard Marx's own scientific pretensions, then it works.