Because it was easy drama, even if for the moment. A lot of choices and events could be labeled as "insignificant" in the long run from one perspective, but the thing is, the significance lies in the moment. Based on what I gather from King's style, the at-the-moment significance and surprise and shock value/etc. is something that he loves to do for the sake of gravitas and drama for the characters he cares for/stars in what he is writing (Batman/Bruce and Selina Kyle/Catwoman in his Batman run).