Great post! I agree with much of what you said.
My interest in reading through old magazine comes and goes; I'll get the urge to do it, and then I'll go many months without having any desire to do so. When I do get the itch though, my motivation includes the following reasons:
It's a nostalgic experience. I have distinct, fond memories of gaming magazines. For example, in an issue of EGM2, they did an in-depth walkthrough of Lufia 2: Rise of the Sinistrals; the only reason I rented the game in the first place was because I wanted to use the guide the magazine provided. Or, similarly, Nintendo Power once featured Breath of Fire 2 in Counselor's Corner; I remember one of the questions being, "what is the best party?", and I was like, "what the heck is a 'party'?" Breath of Fire 2 was one of the first RPG's I played, and again, it was because I read about it in Nintendo Power.
It's fun viewing through the lens of hindsight. I love seeing what gaming magazines said about games, being that I now have the benefit of hindsight. It's cool to see games that were hyped up but bombed, or games that received minimal coverage but were awesome.
It's a cool reminder about how different the world used to be. It's hard to believe that I used to go into rental stores and pick out games on the basis of box art / two-or-three screenshots on the back of the case. It's also crazy to think that I would buy games based solely on a positive recommendation from GamePro or EGM. Today, you have dozens (if not hundreds) of professional/fan reviews at your disposal. Further, tips/tricks/walkthroughs in magazines used to be invaluable. Nowadays, all of that is available virtually instantaneously through a search engine.