There are many styles of parenting.
Any style of parenting CAN produce good outcomes. Young humans are amazingly resilient and other members of society can back-fill missing components needed to produce a productive, well-balanced adult.
That said, some parenting styles produce a higher percentage of dysfunctional adults than other styles.
Viewed from a Developmental or Freudian perspective, children have different needs at different ages. From age ten onward, a big part of their job is to forge an identity that is separate from their parents.
In a word, rebellion.
First they push away from the family, then they find an island that is willing to accept them into their tribe. Then they swim away from that island to find the tribe they want to belong to.
Early on, Mrs ERJ and I decided that we would "freak-out" over hair styles. Not a kick-the-kid out freak-out but a get-excited freak-out.
We wouldn't forbid it but we wouldn't enable it.
Mrs ERJ's thinking was that a kid will push until they find something that affirms they are their own person. If, as parents, we say "Oh, that's cool" to everything, the kid will keep pushing the boundaries until they are roasting a puppy over an open fire in the bathtub.
Furthermore, Mrs ERJ's thinking was that hair grows back. Like the old joke says, the difference between a good haircut and a bad haircut is a week.
Hair gives the kid a lot of latitude for exploring personal expression without limiting future job opportunities; something that you couldn't say about tattoos (that changed a bit since our kids were young).
I wonder how many of the poorly behaved 24 year-olds are stuck at 14 inside because they were never able to get validation that they finally achieved separation from their hyper-cool parents.