Sending our kids to the corner when they are being punished may not be the worst thing in the world, but it may be problematic when it comes to spiritual formation.
If the only time that we are intentionally put into solitude is when we are being punished, then, like the dogs of Pavlov, we will begin to associate solitude with punishment.
St. John of the Cross said that the first language of God is silence and yet we may be raising up a generation of people who fear silence and solitude.
While it my be helpful, using solitude as a means of punishment it may very well constrain spiritual formation.