Newer stoves require a longer cleaning cycle and still do not do as thorough a job as the older ranges did because they do not heat as evenly or as well. The front corners and oven door liner almost need to be cleaned by hand before the cleaning process and, even at that, because they stay cooler than the rest of the liner, some soil vapor might be redeposited in these areas during the cleaning. This temperature differential at the front of the oven is exacerbated in many ranges by the large door windows. Also, in older well constructed self cleaners, the oven liner was a separate piece from the area that surrounded the oven opening. This helped serve as a thermal break to keep the heat from migrating from the oven liner as readily, allowing the front edges of the liner to be cleaned better because they heated up better. I don't know if GE was the only one to use the heater around the front edge of the liner, but that certainly helped clean that area and the door liner.
Another example of the evolving cheapness is the elimination of the heated catalytic smoke eliminator.