[beat]

That's probably because in no small part, "rigorous refutation" is confused with "vigorous refutation" that is shallow and partisan in nature. Hating on Marx is easy; refuting Marx completely in a rigorous manner is hard; doing it without an obvious axe to grind is even harder.

Even to the extent that Marx was wrong in the particulars, he got a lot of essentials right in new and unique ways. More importantly, it's impossible to have a serious conversation about labor that excludes Marx entirely (unserious conversations are another thing). And we've now had over a century of refutations of various types and degrees, from both right and left. Contributing something actually new and significant to the literature would be even more difficult than developing a thorough and academically rigorous "refutation".

Hence, the nitpicking about details from the left, and the unrigorous blanket rejection from the right. Both are far safer ground than trying to introduce breadth on the left or rigor on the right.