Good point. I posted before I'd finished thinking it through.
So under capitalism, personal greed serves as a counterbalance to personal bigotry.
I would say "not really". What you have to consider is that:
1. It doesn't matter nearly as much what you as the owner think of equality, as what your customers think.
If people are willing to pay more to see big boobs, you get Hooters. If you don't cater to them, someone else will. If people pay more to not have blacks in the same neighbourhood, you get people migrating first to the suburbs, then making gated communities. Sure, they pay more and sacrifice their time in commute too, but they're the ones creating the demand, not the supply side. If, say, you refused to sell them the land for a WASP gated community, someone else will. If people pay more to not have blacks in the same restaurant, then you get, well, segregated places. Unless some law or regulation levels the playing field, you as the owner aren't really the driving force there. If you don't provide the supply for that demand, someone else will.
Essentially, it's also very simple economics: supply and demand. If there is enough demand for racism, someone will provide the supply. In fact, under the free market theory if would be irrational NOT to provide the supply when there's a demand.
2. Racism is very easy to sell to the large uninformed masses that make up the demand side.
And that's actually where pure market theory won't help you, because it's based on something trivially false: that every actor involved is perfectly rational and perfectly INFORMED. Which is trivially false when it comes to racism and those pandering to racists, whether overtly or with dog-whistle speeches.
Basically no one will tell you "hey, you idiot, if we stop selling to blacks, economies of scale don't work in your favour. Have a look at this graph of units sold vs unit price. The less of these we sell, the more each of them cost. So you're paying extra if you want blacks, Jews, muslims, women, etc, excluded from the buyers."
Yes, if people were actually informed that they'd get a cheaper burger if they don't exclude like a quarter of the customers, AND if they were perfectly rational, AND only motivated by greed, like free market theory claims, then they'd rationally decide to buy from the place that doesn't discriminate. But that's 3 false assumptions in one sentence.
And the "informed" one is the most crucial one. Actually the way it's generally perceived and pandered to, it's the polar opposite of reality. It's always presented as you somehow end up paying MORE if you let those pesky minorities in. Either because Jews somehow shaft you if you're not one, or because minority X are all lazy unemployed freeloaders and buy plasma TVs with the welfare your taxes provide, or because they're all criminals and thus impose other drains on society, or whatever.
In short, it's presented as you'd have more of just about everything, including money -- hell, especially money -- if only we didn't have to cater to this or that minority too.
Now guess what greed + this kind of premises does to the conclusion. Yeah, no, it's not acting as a counter-balance to it.
Note however, that communism doesn't really make problem #2 any better. Whether or not different pay is involved, or even money at all is involved, the premise is basically the same: society has enough manpower and resources for amount X of stuff, and it has to be divided somehow among Y million citizens. So there'd be more for you, if you could subtract those Z million of lazy freeloading minority guys from the denominator.
If one actually believes that those Z millions contribute bugger-all to X, but take a more equal share from it, as per communist ideals, it's not gonna make one be more egalitarian, is it?