The apparent justification given is kanya dan being the highest of all gifts. Hidden behind this justification is the transfer of responsibility from the father to the husband. This custom must have presumably started during the times when early marriages were the norm as soon as the girl entered puberty. This itself came up because of the risk perception of a girl who had attained menarche and in a way is a statement that the general mass of humanity was unevolved, with unbridled animal and rakshasic impulses amidst pockets of high, noble and cultured people. This was a way to protect the girl.
There is however nothing spiritual about it. Times have changed and women have become independent in every way. More and more couple opt to live independent of the parents, some with the girls or even both parents. The custom, like many others, has lost its social rationale and needs to be given up with the forward march of humanity.
