Not to pile on but the bitterness has been there for a while. I first saw it when Lori Johns popped up on the scene.
To be fair, Shirley did blaze a trail and it wasn't always pleasant for her, if at all. I believe it required very thick skin and a steely grit for her to survive, which in turn, made her an incredibly fierce and accomplished competitor.
However, after helping to diversify the sport, rather than enjoy the spoils of her efforts, she seems to not be fond of the easier path that she helped create for others behind her. I hold her in high regard as a competitor though and wish her the best.