Same reason the flirting vs harassment meme is a thing
And the icing on the cake is from the mangadex synopsis: "Large, grim, popular. He turned down a girl again... What a waste!" Rape is not rape when the guy is attractive apparently.
Really frustrating for the lack of a better word. A good editor would've had them redo that first chapter since i don't think the author really understood where they were going with that scene. Really wish we'd move away from that type of shit in media.