I think it just led to a different type of game, one with pros and cons. I used to like the "old Ars" approach better, too, but the new approach with specific guidelines and specific restriction somehow feels better suited to the how the rest of ArM5 is set up.
I'm not sure whether things have taken us to such a different type of game or simply complicated the mechanics of the current game.
The Hermetic Magic system has always been complex but had the saving grace of being organized logically around the Arts. We still have that complexity but have also added layer after layer atop it. Instead of making it difficult to master the Arts and making difficult magics high level spells within the system, AM5 scatters knowledge through Virtues, with various incompatible system to teach them, and puts a lot of emphasis on breaking restrictions through an original research system that's even more complex and less coherent than the core magic system. To make things worse, restrictions (and the opposite, new guidelines) are scattered through a vast array of publications.
AM5 is a great game but streamlining the core magic mechanics back to something like those of early editions would make it even better.