Why do men uncover their shoulders during Hajj, and does this not arouse some women?

Ramal during Tawaf is to walk quickly with close steps, and Idtiba' is to place the middle of the upper garment under the right shoulder and its ends over the left shoulder. Both are specific to men, not women, by agreement of the فقهاء (jurists). Ramal and Idtiba' were prescribed for men to display strength and capability for jihad in front of the polytheists who claimed that the fever of Yathrib had weakened the Companions. Also, the Prophet, peace and blessings be upon him, commanded men to do so, but not women.

As for a man's shoulder being uncovered, it is not considered 'awrah (private parts that must be covered). Women are commanded to lower their gaze, and they must perform Tawaf away from mingling with men. If these guidelines are adhered to, the temptation will be removed. One must submit to what Allah has legislated, even if the wisdom behind it is not fully understood.