And stoning to death is a pretty common way of dealing with marital infidelity in Iran. So is chopping off the hands of teenagers caught shoplifting. Just because it's common somewhere don't make it right or acceptable.
I'm reminded of how the British stamped out suttee, the practice of burning a living widow on the funeral pyre of her dead husband. A local Raj explained to a British officer that it was a long-standing Indian custom and that they would have to proceed with it. The British officer replied that it was a long-standing custom in Britain that they hung people who did such deeds and therefore the Raj was free to build the funeral pyre for the widow, but the British soldiers would construct a gallows alongside it to ensure their long-standing custom was fulfilled as well.