Because the time spent on one would consume the development time for the other. We don't get as many updates as it is. While there's nothing inherently wrong with expanding the scope of the game, I think it should start once it's almost/already done.
i think make a true end (with harem), good end (with ones love) and bad end ( with no one but girl don't get rape, ntr or death,...) is better. this game was chill and i dont want to see any girls suffer