oppression vs exploitation, and the liberal limit on "classism"

From When we say "class", what are we talking about? | libcom.org: 

The resolution of problem of “classism” is essentially liberal. This isn’t necessarily a criticism. In the here and now, I don’t want gay people to be discriminated against. But I’m basically demanding that liberal democracy does what it says on the tin and treats everyone as equal, sovereign subjects. The same goes for racism, sexism, etc. The culmination of these politics is formal and informal equality as liberal citizens and on the labour market. This is perfectly possible within capitalism.

But when we understand “class” as describing a relationship with capital, the implications are very different. We’re talking about an exploited class, not an oppressed one. I.e. the class has surplus value extracted from it, it is not discriminated against. This cannot be resolved by granting the working class equality with capital. It must result from a resolution of the struggling interests of workers and capital through the expropriation of capital and the construction of a society based on human needs.

This difference has been correctly described as a politics of oppression as opposed to a politics of exploitation. The resolution of oppression is liberation, the resolution of exploitation is expropriation. Only one necessarily points beyond capital.

This is an extremely useful distinction for me, because it explains the well-paid people who are contented to be exploited—they don't feel oppressed. The worst that will happen to them is they'll be fired. Wise capitalists try to keep the obviously oppressed far away from the contentedly exploited, and when they can't, they make the contentedly exploited feel superior—they're house slaves, not field slaves, and they admire Master, and they know that if they get the chance, they'll become just like Master some day—see the long history of slaves in US history who became slavers after they won their freedom.