Guess he figured if he appeal to everyone no one would torrent his game (upon release)
Probably not that no-one, but that the west wouldn't disproportionately torrent his games.
In Japan, fans actually have face-to-face interactions with creators. They go walk around the stadium, buy directly from the creators and the creator bows while saying thank you. I think this closeness with indie content creators makes Japan less likely to pirate or steal eromanga and games.
It's not the same in the "west" where the content creator is an avatar on a screen. Some people don't even interact with the creator or care who they are as they pirate (and enjoy the games no less... You have no idea how many "big" fans of Kamidori Alchemy Meister I've met that don't even know who Eushully is.)
Still... I can't fault them. The games are in Japanese after all. It's like the devs are saying "This isn't for you go away." So people don't generally have any qualms about just taking it to see what the fuss is about.
I don't understand his anger in this regard though. If people didn't pirate literally NO westerner would buy his game. It's in Japanese. He literally only stands to gain in this regard.
Releasing in the US on reputable platforms like Steam is him getting the business sense to finally reach out to the audience he has around the world.