This is the bargain free societies make when they legalize bad things. Take prostitution. You can make a strong case that it should be legalized. You cannot make a strong case it should be respected as just another career choice.
Clearly Mr. Goldberg does not get out much. There are many career choices (legal to boot!) I respect less than those of prostitutes or drug dealers. I will not list them here, because I don't know where people who reading this work, but they exist.
The problem with social stigma as a tool of social control is simply this:
If there is a law against something, then a decent society has pre-established instruments with which this law can be abolished, and the item in question legalized. You establish public debate and you sue in the courts, and you either win or you lose, but you get a stand-up fight.
How the hell do you fight against a social stigma? You can't box with a shadow. Oh, if you're a socialist you can use the state education system (and if you're using the state education system to promote your values
you are a socialist), but if you're a libertarian... what, precisely?
True, there exist opt-outs.
The modern economy, decentralized as it is,
encourages the creation of niche markets – and therefore subcultures and sub-fashions[1]. It's not a coincidence that modern capitalism has given us furries, gun nuts,
hikikomori – and allowed, for the first time, for people to set their own rules. Had I lived in New York, 1929[2], for all its freedom, I would have to go to work every day in a suit, a tie, and a hat. Living as I do in Ashdod in 2009, I work from home and I don't even know what my employer looks like – hell, I could work naked if I so choose, or download Bible Black to my work computer.
But in general, a stigma-friendly environment is constricting – after all, the whole point of social stigma is to get people to avoid doing stuff you think is bad. In Israel, people are used to the idea that “children need frameworks”, and therefore homeschooling is looked upon as some form of disgusting child abuse. The Zionists have worked for years to impress upon gullible parents that the school system is the only place to send the children, and people now have accepted it to the point that you can hear radio hosts insulting a caller who admits her four-year-old isn't in a kindergarten yet - “You're a terrible mother!”
The whole reason a lot of people are libertarian – apart for the moral arguments in favor of freedom – is that they want to do something and the state is not letting them. You know it and I know it.
Your argument is: “Fine, we're not going to arrest you if you or your loved ones do the stuff we don't like, but we're going to suppress them with social ridicule and exclusion to the best of our ability, and restrain them from positions of social success and generally ensure they don't get anywhere in life.”
Now, granted, this is miles better than what we have now, but do you genuinely expect libertarians to go for it?
[1]Gilles Lipovetzky, “The Empire of Fashion”, Princeton, 1993.
[2]Frederick Lewis Allen, “Only Yesterday”, New York, 1964