I’m skeptical about this author’s grasp of the Hegelian dialectic, let alone the Marxian variant.
Critics note that Hegel’s style of dialectical logic was speculative and unfalsifiable
This is a meaningless accusation. The point of Hegel’s dialectic is precisely to remove the arbitrariness of this speculative moment, to ground that speculation entirely in the subject matter without any external reference, i.e. in immanent critique.
If one wants a useful critique of Hegel, look no further than Marx’s own Critique of Hegel’s Philosophy of Right. The problem with Hegel, according to Marx, is not that his speculation is arbitrary. It’s the opposite; it inevitably reinforces the status quo, because the Hegelian dialectic can only justify the object of critique while pretending to negate it.
There is no removing speculation from the scientific process. Ever. Speculation is essential to science. If we must insist on the grade-school rubric of the scientific method, the one that moves like hypothesis — experimental setup — data collection — analysis — conclusion, then the speculative moment is inherent or maybe prior to the hypothesis stage.
Dialectics is necessary in Marxism precisely because it resists positivist, Popperian vulgarization of science. That they cite Karl Popper favorably, and uncritically, says enough for me to dismiss the rest of the article. Certainly, complaints about falsifiability induce eye-rolls.
I would agree that there are many bad interpreters of dialectics, even supposedly great Marxists. This is not a reason to reject dialectics but rather to improve on our collective understanding and on our pedagogy.
Marxism without dialectics would not be recognizable to me as Marxism. Anyway, this has already been attempted by the so-called Analytical Marxism school headed by G. A. Cohen. It is not useful.