Why does the LDS church believe that alcohol was forbidden, despite being common in the Bible?

The Word of Wisdom prohibits members of the LDS church from drinking alcohol, but alcohol is quite common in both the Tanach (Jewish bible) and the New Testament. Why does the LDS church believe that alcohol was acceptable to those in Biblical times, but not now? In other words, what is the reason that alcohol use was a major part of religious life in biblical times, but forbidden now to LDS church members? (I am not a Christian, much less a Mormon, so I apologize if I have made any mistaken assumptions in my question)