I think that both of you are getting caught up on the same thing. 3E (and it's "business plan") was a short term success. Releasing splats increases short term profits but it erodes long-term profits as it quickens the decline of the edition and eventually leads to a new addition (which usually means a time between the 2 editions where profits and revenue dry up and books towards the end of the edition usually sell ).
5E is trying to buck that trend by thinking about long-term profits (evergreen edition, strengthening the brand name, etc.). Yes that means a change in strategy, it also means more focus on the "brand", and less focus on pumping out splatbooks and other short term profit/revenue generators.
From a marketing standpoint they are most likely doing it right.
So if an 8 year run is a "short term success" then what do we call a 2 year run?
Or am I the only one to remember the last "ever-green" product that WotC produced?