And I think it's funny how properly quoting a rule being used in the game system being played keeps being referred to as "obscure."
Well, again, I agree with you. The rule you quoted is no more obscure than any other within the 1e DMG. And I very much doubt that Mr. Gygax, were he alive today, would claim that AD&D 1e was not a complex system.
I think that you will find, however, that when people talk about system complexity, two factors are of great importance:
(1) Does the complexity exist where it should for someone's playstyle? I.e., if you want fast combats, complexities should not slow combat down. If you want to get through a lot of exploration, complexity should exist in terms of longer time periods, so as to allow a great deal of exploration to get done.
Morale rules, for example, are the most complex in 1e of all D&D editions, because Mr. Gygax apparently felt that they were important enough to sustain that complexity. I happen to agree, but if you do not, it will certainly seem like needless complexity.
(2) Is the complexity modular? I.e., can you include or disinclude it without damaging the system as a whole? For example, again, with the 1e Morale rules, if you didn't think they were important, you could easily not use them without otherwise upsetting the game.
The recovery rules you cited is another good example of the modularity of 1e's design. If you liked it (as I did and do) you used it; if not, you could easily choose not to use it.
The easier this is to do, the more "simple" the game system will seem in actual play, if only because its complexity in play naturally falls to those areas where the participants desire complexity.
One therefore needs to look at more than just each individual rule to determine how complex a game is, or how complex a game feels in play. It is, for example, a statement of fact that I can play 1e with or without a grid with equal ease; likewise that I cannot do the same with 4e. In a way, this ramps up the complexity of 1e -- I must decide whether or not to use a grid. In actual play, though, the choice of not using a grid with 1e increases speed of play, if not ease of play. It feels like a net gain.
Effectively, IMHO, when people talk about the complexity of a game, they are not referring to the sum complexity of the game with all its possible subsystems, but rather
the complexity of what they have to actually worry about in order to have a fun game.
I know I am, anyway. YMMV.
RC