His definition of socialism is off. Socialism is about workplace democracy, the workers should be in control of the means of production. The idea also precedes Marx. Marx was famous for pointing out that the economical system forms the humans therein and the existence of class struggle. He also pointed out that the ruling class, the bourgeoisie, would not give up power peacefully. Just as the royalty before did not. His historical example was the end of the Paris Commune to point out that the bourgeoisie would stop at nothing to crush any socialist project, hence the name "Communism".
Thus he called the system in which the workers (proletariat) would be in overall control and the ruling class and everyones needs would be met - Communism. The dicature of bourgeoisie would become the dictature of the proletariat.
Also is pointing out that the Soviet Union "did not work well" is... reductionary to say the least. When the SU was established, all Empires of its time immidiately invaded it and fueled a brutal civil war. Its very existence was a thread to them. Which is also the reason only heavily militarized socialist states survived longer than a few months.
Economically it worked damn well. Russia before 1917 was a poor feudal agrarian state. Under the SU live expectancy grew by leaps and bounds, literacy rose from 20% to 100% to name a few things.
Other socialist states had likewise developments and often did even better.
Cuba under the most crushing embargo of history achieved a lower child mortaly rate and higher life expectancy than the country embargoing it, regulary sending medical help to countries in need (In the Ebola crisis, they were the first to help, and with the most doctors and supplies).
China went from looted by western empires, to looted by Japan, to having its entire gold reserves stolen by the Republic, to food security, near 100% literacy, live expectancy almost as high as in europe, and being the second biggest economic power on earth.
Vietnam went from colonial subject to kicking out its overlords; to kicking out their overlord when it set up a puppet regime in the south; to surviving a chinese invasion; to crushing the red khmer despite US and chinese support of them, thus ending the mass murders in cambodia; to food security and all the other stuff.
As for his example of ostratication: There's a reason the defining slogan of communism is "from each according to their ability to each according to their needs".