Because it's not even maths - it's just propaganda with faked-up equations and a lot of pointless shouting.
Economists are not going to be similarly impressed by anything not written by an academic economist. Most economists teach a theoretical framework that has been shown to be fundamentally useless. -- James K. Galbraith
Haven't heard much about them or their ideas since then (perhaps because, as you wrote in your comment, their conclusions were "not surprising".) Truth unfolds in time through a communal process.
