I am. But not an uncritical one, as anyone who reads my introduction to the Works volumes will see.
My survey and evaluation of criticisms of The Law of Accumulation, just out in Marxist Left Review, identifies some which are valid, although they do not invalidate his theoretical framework or main conclusions.
And, whatever the circumstances that explain his Bundist politics, they had their limitations. The notion that the achievement of the Bundist demand for “national cultural autonomy” could itself contain and neutralize national divisions inside the working class is an illusion.
Of particular significance, he was not immune from Stalinism. Grossman’s assessments of developments in Russia in the late 1920s, notably the first 5 Year Plan, were wrong. Like many members and sympathizers of Communist parties around the world, he did not recognize that by the end of that decade the revolution had been definitively defeated. But the passivity of the KPD in the face of the Nazis’ accession to power, with the support of the bulk of the German bourgeoisie, did shake him up.
For a while, he had a more critical assessment of the role of the Communist International under Russian leadership. But apparently influenced by Russian support for the Republican side in the Spanish Civil War, he again became sympathetic to the official Communist movement from the mid 1930s.
That’s clear in his correspondence. But even though The Law of Accumulation attracted the ire of Stalin’s lieutenant in economic matters, Jenö/Eugen Varga, and were criticized in Communist publications, Grossman never repudiated its arguments. And he continued to make them, even as he made further important contributions to Marxist economic theory. That’s why none of his works were ever republished in East Germany, even though he took up a professorial chair and joined the Socialist Unity (that is, Communist) Party there in 1949, the year before he died.
So there were some slip-ups in his book on capitalist crises and breakdown; there were shortcomings in some of Grossman’s early treatment of the Jewish question; and his assessments of the Soviet Union’s foreign policies after the early 1920s and the 5 Year Plans were profoundly false.
On the other hand, if you want insights into the situation of Jewish workers in early twentieth century eastern Europe, into capitalism’s economic trajectory that arise from Marx’s theoretical breakthroughs and what those innovations were, into the inadequacies of bourgeois economics, into the role of a revolutionary party, or into the relationship between production and early modern scientific thought, then he’s your guy.