Nobody is fighting over whether you're going to be doing site-by-site blocking, because that's too exhausting and people know that.
That's why companies have to exercise moral taste when they do a blanket ban on moral obscenity, and that's precisely the kind of product that people mean to purchase -- curation and tastefulness. It's also why it's interesting for people to fight over this, because they're fighting over a policy of scale as opposed to what goes on in one single home.
And presumably this company would later be interested in dealing with schools and other big institutions, which means their product takes on yet another critical dimension, which is the re-allocation of responsibility for making morally tasteful decisions.
In both B2C and B2B, the refusal to exercise moral perspective, taste, and curation is missing the soul of the product. But of course not all areas of tech is for everyone; some people don't wish to work with advertising companies, and that's fine too, but advertising companies likewise make policies of scale and must exercise moral and political taste.