It seems like the main accusation lobbed against unschooling have to do with the idea that unschoolers somehow exist outside reality:
"Without rules and punishment, how will they ever learn to function in the real world?"
"Sure, I can see how you could unschool your way into being an artist or a writer, but how could an unschooler get a real job like being a doctor or lawyer?"
To which most unschooling parents respond by blinking and looking around, wondering if their homes and children are actually holograms and they've somehow failed to notice until it was pointed out to them. "Isn't this real?" is the usual - and logically sound - protest.
However, I think the naysayers are onto something. Unschooling does allow kids to exist outside of reality - at least, one particular type of reality. Let's reframe the arguments above from a feminist perspective:
"Without being forced to comply with people bigger and more powerful than they are, how will they ever learn to give in to the kyriarchy in the future? How will they learn that their lives and bodies belong not to them, but to whoever happens to be older, whiter, richer, or more male than they are?"
"Sure, I can see how unschoolers could get artsy frou-frou jobs that don't really matter, but how will they compete in a male-dominated profession - the only ones that really count?"
I'd like to suggest that these are the arguments that are really being made - whether the people making them realize it or not. In a patriarchal society, we are conditioned from birth to believe we must give respect to things typically associated with maleness: dominance, competition, cold rationality, discipline, left-brain thinking. Meanwhile, we're taught that we must not give respect to things traditionally associated with femaleness: cooperation, compassion, sympathy, free expression of emotion, creativity, nurturance, right-brain thinking. School, being part of the kyriarchy (the societal system of oppression designed to uphold the dominance of white, middle-aged, wealthy, heterosexual, able-bodied men), is designed to uphold the former, "masculine" set of traits and values. The second, "feminine" set is strongly discouraged by schooling, but is encouraged by unschooling.
School used to be more overtly patriarchal, allowing only boys a pass to higher education and higher pay while ensuring women remained uneducated and housebound. Today girls and women are allowed to attend school, but in a system that shames them (not to mention boys and men!) for exhibiting any sort of feminine tendencies. It sets up a catch-22 where in order to be a success as a woman, one must mimic and compete with men. For feminine, right-brained, sensitive, or introverted people of any gender (because remember it is the association with femaleness that is considered undesirable by patriarchy, not just femaleness itself), the idea of simply finding success with their own natural skills is never brought to the table in school. They must change who they are or risk failure and humiliation. That's how the system keeps people from flourishing in a way that threatens patriarchal dominance.
So when people who, consciously or unconsciously, uphold the kyriarchy first hear of unschooling, it is simultaneously devalued and seen as a threat to their own system of values. Simply put, what they mean by "the real world" is the man's world. What you are doing, when you unschool, is removing your children from a system that says the man's way is the only way. Of course, unschooling certainly can and does produce doctors, businesspeople and other traditional professionals, if that's what those unschoolers genuinely want to be. What unschooling doesn't do is tell kids those are the only things to be. The reason unschooling is so good at producing writers, artists, doulas, homemakers, alternative-school teachers, caregivers, and other "feminine" professionals is because unschooling gives these people more than a snowball's chance in hell at success. It does not stomp on their spirits from toddlerhood on until they finally give up and conform.
So the next time someone asks how your kid is going to get a "real" job in the "real" world, know that this person is, intentionally or not, upholding systems of oppression that are designed to set up most of the population (women, people of color, people with disabilities, the working class, people who don't conform to gender norms) for failure. And know that by choosing unschooling, you're supporting a system that is designed to work with who people are, to allow them a way to succeed without impersonating someone else.
Which one sounds more real to you?