Quick summary of everything that happened before
I remember reading on the first game forums about something like the rat in game symbolizes the pirates, stealing food and loot from the player. The dev really is very spiteful and turned it into comedy gold. Yeah it sucks when the thing you've worked hard on is getting "stolen"/pirated and you're not getting revenue from it, but going full nuclear and even creating DRM that can brick people's PCs are going too far lol.
The more he antagonized the pirates, the more trolls and people that like DRM free games will fight back. Unless he pays for actual good working DRM like denuvo (no active cracker) then most DRM can easily be cracked and he will only look like a fool antagonizing his audience.
It's not like majority of people here (probably 99.9%) will buy H games, either due to principle (some people think it's below them to "purchase" sexual related stuff, may it be services from prostitutes or erotica) or they are from 3rd world countries that have other things in mind before spending their hard earned cash on "entertainment" specially on the adult kind.
But keeping it DRM free is like having an open store that works with "tips". Not ideal for the developer, but the only way you can "enforce" having a DRM is if your game is "big enough" that justifies going the DRM route. Like mainstream games and big game devs/publishers. Most indie games that go DRM will more than likely just tank their sales. Since piracy may actually help "niche games" get some purchases by "offering" a free demo (that is the whole game....) and if people love it then they may support the developer by buying the game. Think of it like a "free advertisement". Which can also help the dev's next games since they can build a reputation/fanbase for themselves.
Things like Black souls, that game went semi main stream and would not have that reach if that H game has DRM and it would probably not have reached its current sales amount.
Many mainstream normal games also are DRM free yet people bought them because of the Quality. Baldur's Gate 3 is one notable example. Also buying DRM for an indie dev can be expensive, and they may potentially lose more money/profit due to the monthly/ up front cost of the DRM and their sales.