I don't mind the locos <= 2.5 hours. That's about my limit, anything more than that and I want a seat of my choice, entertainment, food, water and decent cabin crew.
People blithely assume that the same explosion of travel will happen on long haul if the locos jump in, fogetting that the price of economy travel is well below that of ten years ago in real terms, EVEN with the silly new "green" / budget hole filling taxes.
People might nip to Rome on impulse, fewer will cross oceans on impulse. The dynamic is different.