No, no J_9 not disagreeing with you or think you are a cruel mother at all. You have very good points.
"You see, when children act like this, if they are not sick or injured, sometimes it is because of OVERSTIMULATION.
When you take child into their room and tell them that they can come out when they are in a better mood, it is quieting them, quieting their mind and removing the OVERSTIMULATION that they are being subjected to.
My only objection would be to say "when you are in a better mood" which I am sure you simply mean when you are calmer- your motives are fine. My concern is for those parents that say "go away until your bad mood is gone so I don't have to deal with it at all".
You see, when the child goes in their room they don't have to sit on the bed or lay down, but can play with their toys and lower their stimulation threshold if you will."
My comments are in reference to those parents who are trying to stiffle their children's negative feelings not manage them as you are. They don't necessarily have to be right in front of you, as you point out, to be in a safe place to calm down.
There is more than one way to accomplish giving a child the means to bring themselves back into control.
My comments are for the parent that sends the wrong message to their child in doing this. Not to you.