To the novice, any two dense texts (e.g. Heidegger vs. Hegel) are equally impenetrable. Same goes for most of the Marxist tradition, which has never shied from developing its own jargon. But this opacity to outsiders is a false equivalence; that is, it’s concealing a difference between different jargons.
Some jargons are celebrations of individuality, esoterism, and genius. The point is that the reader should undergo the grueling process of figuring out what is being said, even though it’s difficult, because that way they prove themselves worthy — a member of the elect — and share some small part of the glory that belongs to (and trickles down from) genius. Genius jargon doesn’t have to be rigorous since it’s always sort of art, poetry, performance, in and for itself. 
Marxist jargon, by contrast, is jargony because it’s rigorous, rigorous because it’s debated, and debated because it’s democratic. Only jargon that has been subjected to trial by fire (i.e. a bunch of angry defensive Marxists with an axe to grind) enters the canon. The Marxist canon just is whatever conceptual tools Marxists haven’t found good reason to dispense with yet. Marxist jargon is polished by use, not preserved under glass. It’s brought out to facilitate communication, increase bandwidth, nothing more. The point is efficiency, not reverence. 
The principle “if anything stops working, chuck it out” makes Marxist jargon infinitely more flexible than any genius jargon. It does still pose a barrier to entry, and we need to do lots of bridge-building and translation to facilitate entry. But it’s also legitimate in a way that genius-worship is not, because of the aforementioned democratic polishing. Or, better yet: it’s legitimate insofar as all the above is true. Insofar as it resembles genius-jargon, it can get fucked.
For example, in Scritti su Nietzsche (1980), Giorgio Colli instructs readers on the proper degree of deference with which to approach ideas above their rank: “For Plato, souls are akin to ideas whose compactness is primordial, crumbles through the reconstruction of a presupposed totality, where bounded expressions have the value of melodic and harmonic fragments of an unknown music. It is appropriate to listen to Nietzsche in this way.” [web] — R. D. ↩
For example, in China’s Socialist Economy (1986), Xue Muqiao explains many lessons learned from the material experience of building socialism in China: “We cannot complete our understanding of objective laws by a single move. We must test to see if our knowledge, as manifest in our line, principles, policies and plans, brings anticipated results, is accurate and corresponds to objective reality. Practice, knowledge, practice again, and knowledge again — this is the inevitable process by which we come to know objective laws.” [web] — R. D. ↩