I don't know what you mean by my disagreement with the free market system, but the short answer why a case, like Lochner, can't be decided on privacy grounds under the XIV or IX Amendment grounds is that working your job and earning a living is simply not a private activity.

The first, third, fourth, fifth amendments all embody privacy considerations. Privacy rights have been narrowly shaped by caselaw to deal with issues of personal autonomy (as Justice Brandeis recognized in the 19th century- "the right to be left alone"). The privacy rights are personal, rooted in family, procreation, child raising, marriage.

Precedent has resisted extending the rights to commercial activities, like running a bakery in Lochner, an activity that requires hiring people, paying rent, buying from vendors, selling to others, basically an enterprise conducted in the public, openly and for profit.

government actions that impinge a privacy right, like criminalizing homosexuality (Bowers), abortion (Roe) involve a privacy right under the Fourteenth. This is not to say the law automatically fails, but it is subject to strict scrutiny requiring the State to show a compelling state interest to justify the infringement as the first prong of strict scrutiny test.

Contrsry to belief, the Court has been rigid in extending the right of privacy beyond private considerations.

The court holds government intrusion into the regulation of all bakers to a rational basis test, but when the government enters the bedroom to arrest two consenting adults for not having sex the way the government mandates, then, yes, the strictest scrutiny is warrantesd.

As I said above, I disgree with a constitutional right to abortion. But it's not because of privacy as a right. I believe that a law precluding abortion should be subject to strict scrutiny as it impacts private, procreative rights. I feel that the state has a compelling interest in safeguarding the prenatal life.