Discrimination as a market commodity

This isn't about the gypsy/traveller situation per se; but is just tied in to various commentary I've picked up in a wide area mostly from bigots. The argument that is made or at least colours their comments is that it shouldn't be up to the government to punish people for discrimination. People should be allowed to discriminate and it's up to society to penalise them for doing so if it wants to. If it chooses not to who are the government to step in and say that we the public are wrong? It's an application of free-market forces to society.

Beyond the obvious that we've all witnessed first-hand exactly how good such forces are (not withstanding those who still argue the current situation is due to the fact the markets weren't free enough) the argumental logic roughly follows as so:

A supplier decides they're not going to serve a particular minority.
If the public continue to use that supplier then it demonstrates they're happy with such bigotry and life continues in this fashion.
If the public aren't happy they will cease to use that supplier and the supplier will note the drop in sales and thus remove the prohibition.
Thus speaks the market/public.

It'd be a great argument if it weren't so flawed. I'll leave the biggest flaw to last and start with the assumption that if people continue to use them they're happy with bigotry. One of the fundamental postulates within free-market economics is selfishness. It doesn't always apply, but I'll use it as is.

Given selfishness the question of who is still using the supplier becomes simple. It's no longer just a question of supporting bigotry, but of not inconveniencing oneself.A rough split is between those whose inconvenience outweigh their conscience; and those whose conscience outweigh their inconvenience. Now that includes those who conscience may be either for or against the bigotry; some people may chose to inconvenience themselves because they support these views.

In any case those no longer shopping will either be those with a strong conscience against bigotry who will accommodate the inconvenience; and those with a weak conscience who didn't really shop there anyway. As the latter don't really count from the store's perspective a dent in the profits will only appear if those with a strong conscience form the larger group. If this isn't the case that doesn't equate to support for bigotry; perhaps only guilty consciences from those who still shop there.

This now leads to another postulate of a free-market - freedom of information. If we state that profits have dropped due to this prohibition the logic is to remove such. However that is assuming that the company match the correlation to the correct cause. It may be they think profits have dropped due to a lowering of demand; a fall in the economy; changing the layout of the store; altering their logo. The only way they can definitely match up to the 'right' cause is if people tell them. That means the people who aren't shopping there have to add to their inconvenience to tell them; or those who do still shop there have to mention it (which would imply their own selfishness).

Finally the largest flaw. If the public are against it and have told the store it will remove the prohibition; why? Again the selfish postulate is used in that the store wishes to maximise profits and as the prohibition counters that it has to go. Except if that's the case why was it enacted in the first place? Remember this is a sign actively removing part of a customer base from the store. The logic used to remove it prevents it from ever being put in place unless the store considered that the loss of such a market segment would be made up in some other fashion which implies the pre-existence of bigotry which is what we're trying to prove or disprove.

Hopefully I've shown that that a free-market doesn't necessarily equate to public opinion and therefore shouldn't be used as the basis for determining the actions of a society.