That is the belief of their faith. Just as Christians believe in modesty.
We should be sensitive to what is culturally acceptable and keep in mind what Scripture tells us: we should try not to put a stumbling block in the way of a brother (Romans 14:13). In Philippians 1, Paul says: “And this I pray, that your love may abound yet more and more in knowledge and in all judgment; That ye may approve things that are excellent; that ye may be sincere and without offense till the day of Christ”

Just because you have a belief system doesnt make it right. In the past, many men thought it was their right to beat their wives any time they saw fit. Doing that is abuse, as is only allowing eyes, hands and feet to show. Abuse is abuse, irregardless of one’s religious beliefs. Your comment says to me that you would defend abuse because it’s their custom or religion. WRONG no matter what side you look at it from. Abuse, is abuse, is abuse, is abuse. FULL STOP.