Still, I want to correct the author that there is no restriction on interfaith marriage, the law is for conversions happening after interfaith marriage. Law does not talk about prohibiting the marriage but talks about stopping forceful, deceitful, enticement or conversion to other religion against the free will of an individual.
Facts have been taken into account and questions are asked as to why a conversion is necessary if a person marries in another religion. One can continue to practice her/his own religion even after marriage as for such cases Special Marriage Act is already there.
Changing religion is a personal choice and must happen through free will and marriage should not be used as a means to do so which many times is done with malafide intention.
If we look at any law which has been enforced is for curbing some ill happenings or to prevent the masses in general. For example, Dowry Act, SC/ST Act, POSCO, etc., all these laws have been enforces to prevent a section of society and provide equal rights to all citizens. No one should suffer because of breach of trust by other and should have a legal remedy in case anything as such happens in future due to his/her current decision.
Only thing that needs to be taken care of is that, the law should not be misused as many times people misuse most laws to take revenge or to extract money, etc from other party.
Live before you leave.