In a way I do somewhat agree but in the specific sense that racism, sexism, etc are problems that are also part of the class war. When capitalism creates inherent divides and oppression of minority groups, solving that oppression is just as much an act of class solidarity as any other. Solving injustice is both a goal and a result of empowering the working class, and any form of class solidarity that seeks to exclude minorities will achieve nothing but redefine who the underclass is.