The basic issue is simple. Some people think strict rules and guidelines for how students dress is helpful to an educational environment. Others disagree.
Most people on FR frown upon the way public schooling is structured in the first place. In a private school, this isn't an issue. You don't have to send your kid there if you don't like their rules.
The only strong reaction I have to this article is the continuing futility of public schooling.
How convenient for the state. They make education cumpulsory and mandatory, and then provide, AT TAXPAYER EXPENSE, the only "free" means of fulfilling their mandate. That sounds like involuntary servitude to me.