Too Young for Kindy?

What is the best age to send a child for nursery, playschool or kindergarden? I suppose it depends on each child and their stages of development. However I am totally against sending them too young when they are not ready for it.

While I was shopping for kindergardens recently, I saw this 3 year old little boy who looked so traumatised and lost. He was running around looking totally lost and confused and bawling away. He ran to a table and tried to grab his little bag, then he ran to look for the door but couldn't find it and the person in charge simply said "See you cry some more, now you can't get out."

He looked totally pitiful. It was his first day apparently. I wonder where are his parents. I wonder why they have sent him to kindergarden at such a young age. My boy who is 3 is constantly having separation anxieties from me even when we are in the house and I am out of sight. What more when they are left in a strange environment without beloved mummy or daddy. I wonder, I wonder, I wonder and I feel really sorry for the little boy.