I offer this quote by Gary Gygax. This was written a short time before the 1e DM guide was released, but after the players guide and monster manual had already come out. There is a lot that could be said about this but I think I'll let each reader digest it for himself/herself.
From The Dragon #22, February 1979
An excerpt from “Dungeons & Dragons, What it is and Where it’s Going,” by Gary Gygax
Fanatical game hobbyists often express the opinion that DUNGEONS & DRAGONS will continue as an ever-expanding, always improving game system. TSR and I see it a bit differently. Currently D&D is moving in two directions. There is the “Original” game system and the new ADVANCED D&D® system. New participants can move from the “Basic Set” into either form without undue difficulty— especially as playing aid offerings become more numerous, and that is in process now. Americans have somehow come to equate change with improvement. Somehow the school of continuing evolution has conceived that D&D can go on in a state of flux, each new version “new and improved!” From a standpoint of sales, I beam broadly at the very thought of an unending string of new, improved, super, energized, versions of D&D being hyped to the loyal followers of the gaming hobby in general and role playing fantasy games in particular. As a game designer I do not agree, particularly as a gamer who began with chess. The original could benefit from a careful reorganization and expansion to clarify things, and this might be done at some future time. As all of the ADVANCED D&D system is not written yet, it is a bit early for prognostication, but I envision only minor expansions and some rules amending on a gradual, edition to edition, basis. When you have a fine product, it is time to let well enough alone. I do not believe that hobbyists and casual players should be continually barraged with new rules, new systems, and new drains on their purses. Certainly there will be changes, for the game is not perfect; but I do not believe the game is so imperfect as to require constant improvement.