No, it's because it'd be stupid. For example, it is not the government's business if a consumer chooses to go to Jamba Juice because they like Mormons, but it most certainly is their business if Jamba Juice chooses to hire only Mormans. You can claim it's the same all you like, but the law is on my side, it is different, as it should be.
A consumer is free to discriminate by whatever criteria he wishes when purchasing goods, the employer is not allowed to do so when hiring labor. They are different. Employers are in a much better position to abuse their power and when they do it has a far greater impact on the person being discriminated against; that's why it's different and that's why we regulate them.
Since when has stupidity disqualified legislation from being passed into law?
> A consumer is free to discriminate by whatever criteria he wishes when purchasing goods, the employer is not allowed to do so when hiring labor. They are different.
Congress has been trying to alter the laws of nature with legislation for years. That doesn't mean that the law is a reliable predictor for reality, though.
"...sex, race, age, religion, or ethnic group, or individuals with disabilities..."
which would also be particularly immoral reasons to boycott a business. The main reason there's no equal opportunity law against boycotts is because it would be rather unenforcable--I would certainly consider it reprehensible (though perfectly within one's legal rights) to boycott a business due to the race, sex, religion, etc. of the proprietors.
Other than that, US employers have the right to either continue or terminate employment "at-will". Things that we would normally boycott companies for, like putting rootkits on people's computers or engaging in unethical business practices, are also normally acceptable things to fire employees for.
And considering that the purpose of employment is for the employer to purchase the services of the employee for an indefinite period of time, how is it not a special instance of the producer/consumer relationship? What else could it be?