Primarily there is a complete lack of a solid curriculum that moves the child ahead. After a level 1 class for the 20th time from someone who is not perfect in level 1 yet, the kids loose interest and respect.
So if there is some co-ordinated effort in creating a curriculum, for properly thought out 'levels'/age groups/grade etc, other things will happen.
Guidance as often parents are interested but not sanskrit experts themselves.