What a weird piece. The heart of the argument seems to be that if one is to be a Marxist that one must be 1) poor, and 2) chaste and to be otherwise is hypocritical. Just state the point and be done with it.
So I'm not sure where the presumption that a socialist must give away his wealth or live modestly comes from. Marx and Engels saw the first step of revolutionary activity being to understand and investigate, bit they were also part of various practical organisations such as the IWA, and the Manifesto was itself an on-the-nose propaganda document.
Why doesn't the Queen give away her throne for the good of her country? Because the boost to the economy from the tourism generated around it helps even more. As it turns out, we can imagine that the world would have been very different and the pair of theorists much less consequential had they spent their energies on philanthropy rather than burning the midnight oil at the British Library.
I think this is terrible for society and the younger generations.
If I was offered the option of becoming a landlord or the like and making good bank that way of this whole shitfest I'd gladly and quickly accept and on the other side donate some of the money to campaigning for a party against this mess. Nobody would to come around and call me a hypocrite for that and expect me to think highly of them.
Systems change over personal change.
Engels was born into a rich capitalist family. Him giving it all away does nothing to change the underlying systems.