This quote, from pg. 7 of the 1E AD&D DMG, seems most appropriate for many of these posts...
"The danger of a mutable system is that you or your players will go too far in some undesireable direction and end up with a short-lived campaign. Participants will always be pushing for a game which allows them to become strong and powerful far too quickly. Each will attempt to take the game out of your hands (out of the DM's hands) and mold it to his or her own ends."
-E. Gary Gygax
The man knew what he was talking about.
Crucially, though - no he didn't.
Sorry if that's slaughtering some folks' sacred cows, but Gygax wrote this stuff in ignorance of the Threefold Model, GNS and later game theories which have developed and informed play since the early 90s.
So some of it is simply outdated, inherently assuming specific modes of play, social contracts and creative agendas which weren't necessarily true even in 1979 and certainly can't be assumed now.
Other sections of the DMG were pretty silly even back then - attacking 'problem players you deem worthy of saving' with ethereal mummies, bolts from the heavens and lowering their stats until they do what you say - and look, to me and others, both hysterically funny in their pomposity and terrible, dysfunctional advice.