Radfems dont oppose class unity, we just disagree w you regarding how classes are defined. We want class unity, but it cannot be achieved if you cannot meaningfully and accurately define what kind of people make up a certain class of people.
Radical Feminism opposes the unity of the working class and its allies by drawing the lines of division across gender with the theory of the so called "sex class." This Radical Feminist theory, however perfect or imperfect it may seem in books and online debate forums, is a disaster for real life organizing.
In the union struggle, women workers are told by "sex class" that they have more in common with their female bosses, the ones exploiting them, making them extremely poor, putting them in unsafe working conditions, denying them maternity leave, taking advantage of the gender pay gap to reduce their pay, etc., than their men coworkers, who are being exploited in a very similar way. According to this mindset, women workers shouldn't form unions with men workers to peruse their interests, but instead side with their women bosses against their fellow workers.
Just under half of the working class is women in the US, meaning that if the idea of "sex class" was adopted on mass it would become impossible to form effective unions as one sex would always be scabbing on the other, likely whichever sex shared its sex with its boss at any given workplace. Clearly it is not hard to see which class benefits from this arrangement.
In other sectors of organizing, the theory of "sex class" is just as detrimental. Should women tenants' side with their landlord, the one who exploits them, fails to safely maintain their space of living, shortchanges them and threatens to evict them, so long as she is a woman? If tenants are mobilizing to form a union to fight back against their landlord (which can often be a life-or-death struggle), the theory of sex class would have the women tenants either sit it out or kick out the men tenants, either way it would set up the struggle for failure. Meanwhile the landlord (man or women) would be the only beneficiary.
Class unity means unity of the Working Class and its allies. Sex Class means division and nearly halving our fighting strength. The theory of Sex Class, no matter how good it sounds in your literature, simply doesn't hold up in real organizing.
To quote the 1st addition of La Obrera
These organizations might be created because of a so-called “radical feminist” political line, as a spontaneous separatist reaction to misogyny and other problems of chauvinism in a male-dominated political space/organization, or because of a misapplication of the correct desire for distinct organizations in the women’s sector...Some of these organizations have the potential to be play a progressive or class-conscious role in certain situations, especially if they are struggle-focused, but ultimately in most cases these organizations play an almost entirely negative role in the revolutionary women’s movement. They promote the illusion that our liberation can be won without the participation of and leadership alongside men, that our struggle can be separated from working-class revolution. The institution of private property, the origin and main sustainer of patriarchy, cannot be defeated without socialist revolution and without the participation and leadership of all members of our class, united as one.
Revolutionaries need to build class unity by struggling against Chauvinism and patriarchal tendencies in our organizing, because we know that men are capable of being champions of women's liberation just as much as women are, and that working women can't achieve liberation without the whole class achieving liberation.
Women hold up Half the sky.