Why are men and women segregated in Mosques?

Muslims go to Mosques to pray to God and concentrate into the words of Quran they recite during their personal prayers. If beautiful women are near or in front of men, how can they concentrate in their prayers. Same way if young handsome men are near and front of women, they will also get distracted from concentrating their prayers. For only these reasons women are front, then one or two rows of children and then are rows of women. This arrangement was started by Prophet Mohammad SAW and Muslims love to follow every thing he told us to do for purity of prayers and our daily lives.