The reason for the lack of an official English translation of the game is largely due to the cost and complexity of translating a game with a significant amount of text, character voices, and audio. The game's developers, Marvelous Interactive Inc., likely considered the market demand and decided that an English translation would not be profitable.
In the absence of an official English translation, fans have turned to alternative solutions. As mentioned earlier, fan translators have created unofficial patches that provide a makeshift English experience. While these patches are not perfect, they do offer a way for fans to experience the game in English.
While there is no official word on an English translation of the Ouran High School Host Club DS game, there are several reasons to believe that it could still happen. The growing popularity of the series, thanks in part to the success of the anime and manga, has created a renewed interest in the game.