there is a difference between people scanning to "get a gander" and those scanning and maintaining professional bearing--much as there is among nurses of both genders, OB/GYNs, and the like. I do not find it abusive to be fully scanned given that I know it will happen beforehand.
i would bet dollars to donuts that those saying "it's no big deal" are not women (and even if so, are not those who have endured such harassment). As for the chance that there could be a pervert somewhere, that exists everywhere--but it (presumably) doesn't stop you from leaving your homes each day.