Maybe NG and Airbus "took a view" that it was not going to be viable and "let" good ole Boeing to suffer all the grief and hassle that has proven to be the case. As for using very very old engines, makes me wonder if GE decided that they did not wish to support their old design CF6 for many more years to come which left only PW. Let's face it, they would have only chosen an American built engine after all the
PR "moaning" etc that went on when Boeing did not win in the earlier "contests".