There are two different things competitive runners pay attention to:
times/ records, and place/wins.
New everything (shoes, nutrition, training, tracks, etc.) will help runners eclipse the historical times of the past. There is always, and will always be, "something different" happening at any point in time.
But you cannot take away how well you placed against others.
I respect Des, her consistent results (both times and places) and her willingness to speak out.
I believe her statements are not complaining about the new shoes.
She has the perspective to realize that there is always something different happening, and her very good times from the past are not looking so good now.
Good for her that she had that Boston win, 2nd at Boston, made those Olympic teams, etc.
I believe she is realizing that people will not be very impressed by her times in the future.
But times and records are still important. Not so much historically but they are relevant to the era during which those times were achieved. Top times, course and world records are still coveted, because they indicate that in that era, those runners were some of the best. Those that set course or world records beat the historically best times. But those record times will be eclipsed in the future.