Ease of access to quality legal representation is also an issue as you implied. No matter how good the law is, your average person won't know all their rights. Reminds me of people who sign non-disclosal agreements when they could have written a book and gotten 100 times the amount from the publisher than the compensation they received from the offending party.
Something to consider though the practice might be very, very rare in certain locations and somewhat common in others: At times a woman might be very well aware of the criticisms of a dowry yet is personally choosing to engage in that practice. Now one can ask whether it was out of pressure or was it out of free will?
I think you missed the point. The dowry is essentially a bribe to make your husband family treat you better. In the case of one of the women who died, her family bought her husband a car. Her brother is quoted saying :"If you wanted an educated man, you need to pay a dowry" @MangoGuy Pointed out that it is used to entice men of better background or marry up. It is pretty hard to say it is of free will. Families go into debt to procure a "suitable" dowry