My son used to play Barbie with his older sisterHe grew out of it.
Now they knit together. Heck, I even learned to knit.

But they both have many other diverse interests.

We work very hard to not enforce gender stereotyped play, but I agree strongly in principle with parental discretion in limiting cross-gender behavior it when it becomes a problem. The extreme cases described in the diary are examples where the parents let the behavior get out of control for years and years.

It becomes a problem when it egregiously violates social norms.

For example, it's not appropriate for boys to wear dresses to school unless it's a costume. And parents who don't act before this becomes a risk (as evidenced by a growing preference at home) are playing with fire.

I can manage my own toleranceI can't manage the tolerance of every person that my child encounters.

Children are not social experiments.

Children are not exercises in public demonstration of moral outrage.

Children are not vehicles for political theater.

You get one chance with a child.