those assertions are founded in history and the actual positions of marxism, it's many sub-genres, it's precursors and the policies of the Brothers Gracchi.
Ye Olde Tyme Marxism, the tpye Comrade Marx used to make only sells to those who have no hope, which is why it flopped in germany, flopped in intaly, flopped in britain, flopped in france, and only found fertile ground in the last realm of serfdom, Tsarist Russia.
it had to be re-worked to sell in china (Maoism) italy (Fascism) spain (Fascism) germany (Nazism) scandinavia (Type 2 Fascism, democratic socialism) south america (Mostly Maoism with a little Fascism mixed in) etc etc etc.
meanwhile the catholic church has been running the same drag on the religious tip since the reformation, and the age of enlightenment. when the bouregois stop giving to the church, you gotta appeal to the proletariat, and as always, the dumber and more hopeless they are, the easier it is to sway them with you grand schemes and big talk.
and yes, it all came from the demagoguery and pleb pleasing rabble rousing of the Brothers Gracchi, who were in fact, like Marx, Engles, Stalin, Lenin, Trotsky, Mao, Mussolini, Franco, and every pope ever, the dilettante sons of the priviledged class, scheming their grand dreams from the comfort of their luxurious salons (or in the case of the Gracchae, their Tricliniums...).