Regarding the logic there. I'm assuming during the roughly 10,000 years of the 2nd and 4th ages at least one magical civilization reached a level of complexity requiring a magical Internet to function.
Wyrm makes a good point about the functionality of a Draconic Memory gem not necessarily being the same as a hard drive. But given five hundred generations of functional magic users from the 2nd and 4th ages, it's logical that one of them could figure out how to magically store/retrieve data.
Once a magician invents magical data storage, things would take off. The first computer hard drive was developed in the 1950's and we had a functional world wide web only two generations later.
First, why do they need to magically store and retrieve data? That's what books are for. And, y'know, that's what they
use. Mages compete against each other for power, for knowledge, for influence; for your little 'magical matrix' to exist, there needs to be an openness that just doesn't exist in a standard fantasy realm.
Here's the thing: at no time during those past eras was a republic considered a workable concern. Pre-high-magic, everyone is preparing for the Horrors; post, everyone's trying to survive the ones that are left. At all times - 2nd age, when dragons ruled, and 4th age, when metahumans were the growing power - there has always been a dominant ruler. Across the span of
real human history, the Democracy and the Republic - all methods of ruling of, by, and for the people - is an
aberration. Rulership by a small cabal or single individuals is the rule.
Which is more a simpler explanation?
A. Something as complicated as the Resonance Realms spontaneously manifested?
B. Something intentionally built the Resonance Realms?
If that's true, apply Occam's Razor again.
A. Something as complicated as the Resonance Realms was built in the 1st or 3rd ages when there was no magic (and to all evidence no sign of technology)
B. Something as complicated as the Resonance Realms was built in the 2nd and 4th ages when magic was available.
But yeah, it's just a theory and not one I expect the game developers to do more than hint at like they have with the concept of technomages.
... I'm not going to go too deeply into how screwed up your thinking is, here, in part because discussing RL religion (which is where your use of 'Occam's Razor' is heading) is
verboten on the boards.
I don't expect the game designers to come within ICBM distance of it, because for it to exist, you need Liberty, Fraternity, Equality, things that just don't exist in the 'fantasy world' of Earthdawn 4th, or whatever you want to call the 2nd World. The Resonance Realms can be explained as a
whole bunch of things - quantum/superstring echoes of elements of the Matrix, a functionally subdivided global sub/superconsciousness, fragments of the technomancer's own mind, 'deep back-door' creations of Psychotrope/Mirage when she was creating places for the healed psyches to be able to go and heal further.
Whatever you decide, understand that your 'mystic Matrix' is your little playground, and is going to get you snorted out of the room pretty much anywhere else; it just ain't gonna happen, because if it does, you wind up with fun things like dragons, IEs, and global cabals fighting over the power points, fovae, and all the other Seriously Weird Shit that the 6th World has for us, just multiplied by about a zillion.
Whichever way you decide, enjoy.