Frankly, if my husband 'liked' young women's profiles, or leched at women when we were out, I'd be grossed out that he was a pervert who saw women as sexual objects, not threatened!!
As for porn, I think for many women, there is an element of feeling bothered that while they're dealing with the bodily changes that come with bearing their husband's children, their husband is too busy wanking to potentially exploited or raped young women who don't look anything like them, and who are doing gross or painful things they don't ever want to do, to do the housework, help with the children, be attentive to her, or otherwise be a useful human being.
So it's frequently all of those things, or at least multiple of them. Not all of them have issues with ethics as they're not always well-informed, but I think most do consider it exploitative.
A lot of women, though, have the attitude beaten into them by society that men 'need' porn and they just can't stop men from watching it...which is where I think you then start to get insecurities creeping in.