The reason why many sectarian parents want their children to become hafiz (Memorizer) of the Quran in childhood age is because of the selfishness of the parents.
Their mullahs and imams told them that if any of the children will become a memorizer (Hafiz) of the Quran then his/her parents will wear a crown like a sun also parents and other family members receive intercession.
There is no such thing in the Quran so the whole concept of forcing children to memorize the Quran in childhood came from man made hadiths which attributed to the prophet after his death and invented during Abbasid caliphate.
Here are the hadith attributed to the prophet:
1- Mu’adh al-Juhani reported the Messenger of Allah (ﷺ) as saying:
If anyone recites the Qur’an and acts according to its content, on the Day of Judgement his parents will be given to wear a crown whose light is better than the light of the sun in the dwellings of this world if it were among you. So what do you think of him who acts according to this ?
Grade : Da’if (Al-Albani)
Sunan Abi Dawud 1453
Book 8, Hadith 1448
2- It was narrated that ‘Ali bin Abu Talib said:
“The Messenger of Allah said: ‘Whoever reads the Qur’an and memorizes it, Allah will admit him to Paradise and allow him to intercede for ten of his family members who all deserved to enter Hell.’
Grade : Da’if (Darussalam)
Sunan Ibn Maja
Book 1, Hadith 221
I don’t think parents care about their children who are abused and beaten by Imams and Mullahs, they just want to wear this crown in paradise at all cost and hoping for receiving intercession!