Calling the writer incompetent because you can't comprehend what a full-face blush, pounding heart, and a freaking lightning bolt imply is a bit harsh. Manga is a visual medium and they put every possible visual cue into indicating that the maid was genuinely infatuated
Was anyone really arguing that the maid wasn't infatuated, though? Rather, the entire discussion from the crowd who dislike it almost entirely revolves around the playful "blackmail" angle, or a personal distaste for rich top x maid ("poor") bottom. As Kirin notes there's a very good reason that gap stories, even in manga, strongly tend to empower the less well-stationed.
That said, while this thread certainly appears to be a complete outlier, I don't really have much patience for it. No 4 page oneshot demands discussion this divisive, heated, and disrespectful. It's disappointing.