This is based on the law that in a class-divided capitalist society, the interests of the capitalist class and working class will remain irreconcilable, antagonistic, in opposition until the end of capitalism. There is a clear line of division and opposition between the ideology of the working class, Marxism-Leninism, and the ideology of the capitalist class, bourgeois ideology. The two class-based ideologies emerge from and are molded by the objective class reality. They do not blend, harmonize or converge. There is no third ideology.
Ideology is one of the three main forms of the class struggle.
The other two are politics and economics. In a class society, the class struggle sets the rules of the game. We can choose to be on one or the other side of the battlefield. There is no room for sitting on the fence. The ideology of the capitalist class lacks humanism.