Is it just because the child has to be prepared to go to a primary school? Or because the mothers need a break, so that they can do their own thing for a few hours every day?
We all know that there’s more to pre-school than just the ability to read/write alphabets or cramp some maths operations, but can we state it explicitly?
The reason why a child goes to pre-school is, to be exposed to an environment which fosters rapid development of her brain. The development has to enable a child to function as a useful member of society in her personal, social and professional life. Since 90% of a child's brain development happens before the age of 5, the pre-school years are crucial in an individual's life.