Well, I don't know any unschooled kids who have ended up as criminals. And you can have kids who grow up with rules and end up being very bad people. But let's take this concern seriously and look at it in the context of unschooling.
First of let's make a distinction between growing up without rules and growing up without guidelines.
Rules imply control, guidelines imply participation and respect--a sense of everybody being in it together. Rules invite defiance; "You will obey" while guidelines suggest guidance, caring and concern.
I think once we can make those distinctions in our minds, we will have a better approach to parenting.
"Discipline is helping a child solve a problem. Punishment is making a child suffer for having a problem." - L.R. KnostI like this quote but even here, there is room for improvement: The word 'discipline,' implies punishment and 'power over another' and that is not what we want. Rather, we want to encourage self-disciplined individuals.
So unschooling is not about ignoring inappropriate behaviour in your child. It is taking responsibility and acting as a parent. Guidance, gently correcting the child, modelling, being respectful are all natural ways of encouraging self-discipline and respectful behaviour.
Also, since unschooling is about encouraging thinking, don't be surprised if your child challenges and disobeys unjust rules. They should not blindly obey rules. If the rule is plain wrong, do you really want your children to follow it? My kids are a case in point. At high school, there have been many incidences where my children have challenged, (politely but persistently) ridiculous 'rules' and injustices. They have had to dropout of classes if the teacher has been blatantly sexist or discriminatory. My oldest had her work challenged: "Do you ever do anything that is not political?" more than one teacher has asked, be it in art ("Can't you draw a pretty picture?") or advocating for a unisex washroom in support of trans youth. She continued to work within her vision despite the 'status quo.'
Yes, unschooling is about freedom but where did people get the idea that structure is forbidden? There is nothing wrong with structure where and when needed! Routines and structure can be a source of comfort, and clarity to many people. Knowing what is coming next in your day has a grounding effect so no need to be fearful of setting a routine if it helps with transiting and a peaceful household. There is nothing anti-unschooling in being organized. There is freedom in being organized and being able to respond quickly and efficiently should the need arise.