From my understanding of it all, Luger just wasn't getting over enough. Vince initially wanted to give him the belt at Summerslam, but he wasn't over enough, so they tried to extend it to WM but by then Bret Hart was clearly more over, so he went back to him. Royal Rumble 1994 played a big factor, because when they did the double elimination, the crowd went crazy for Bret and booed Luger. And it was in NY, where Vince pays the most attention to feedback wise. That didn't make the final decision for him, but it's kinda what tipped the scales in Bret's favor to get the title.