Why? Marxism refers to the work of Marx and Engels, who are forefathers of the criticism of capitalism (along with other 18th century anarchists and socialists)

Why? Marxism refers to the work of Marx and Engels, who are forefathers of the criticism of capitalism (along with other 18th century anarchists and socialists). I see no reason to get rid of the term or use other terms; I base my reasoning of Marx's work and Engels's formulations and I'll be sure to give the great men their credit.