It's a materialist/Marxist definition, hence the

Because Marxists are like

https://en.prolewiki.org/wiki/Fascism

All successful labor movements and mass organizations in the past have included teaching others how things work, handing out pamphlets, etc.

And so we can choose to act towards restoring definitions to words with important meanings, so that we become capable of discussing the things they signify again.

If we don't use words as they mean, but instead use unorthodox terminology, then we allow the significance of such words to be lost, with no standardized alternatives in common use - i.e., no alternatives that are any more clear than the original word.

There is a war on language. It's primarily a subset of the class war. We can surrender, or fight what is probably the simplest fight of our life: We can use words as they were meant to be used.