Yes, the main reason why children are plucked from the beauty and tenderness of life and are placed in the harsh, inhumane and utterly inappropriate circumstances is POVERTY. just wonder by yourself that are the children who are educated and are nourished by all the facilities, are they forced in an act like child labour? No.
the low economical and financial status of a family are the reason why child has to be involded in earning and contribute for the betterment of their livelihood. Except poverty, many factors such as Social status of a family, lack of education and unawareness as well as ignorance to other social evils also contribute in strengthening this punishable offence.