If transactional sex becomes the norm, while amorous sex becomes scarce, there a few unwanted consequences for the whole society. A few examples: the access to reproduction for the poor is decreased, men in particular feeling unwanted, unable to find a partner and in general feeling uninvested in the common good, which inevitably leads to violence. Yes, it is extreme, but incels in the Western world are a thing and so are 30 million Chinese men who will not have a partner because there are fewer women in that generation.

This is why in general it is frowned upon by "certain members of society" as you call them.