Assuming there is such a reason - and I am happy to take your word for it - that was / is not the ground for tolerating the practice here. In India that right is currently granted on grounds of freedom of religion, not after some study into whether such a practice makes sense. There are plenty of other such practices that are long abolished (such as child marriage) that made some kind of sense once upon a time. I would put polygamy into that same bracket. (as a matter of fact even hindus practices polygamy before it was criminalised in the 50s).