Again, that's surely part of the strategy. Opposition to unpleasant content inevitably draws in the "DAMN THOSE LIBTARD SJWs CENSORING ENTERTAINMENT!" crowd, which in turn draws more attention to the source material. Hatred was universally considered to be a mechanically rubbish game, but a fair number of people bought it just because it was seen as an edgy pushback against feminazis/cucks/snowflakes/insert other silly insult here.
If Desk Plant made a visual novel about something respectable, chances are pretty much nobody would play it or even know about it. Now, with a product called "Rape Day", at the very least, they've ensured that the dark underbelly of society will support it.