I'm of the opinion that Porsche felt the series had run it's course, and didn't want to commit the resources to redesign it. I know the 911 is
evergreen, but the 928 didn't have the rabid following that the rear engine cars do. The 924/944/et-al is another example. Great car but....OTOH, because of this, a supercar that would have been out of reach, ....is obtainable by us, the gearheads.
-K