I see it less about needing a guide and more as elements hidden for the player to discover on their own. I feel it would be pretty easy to find all the augments in IV without a guide. I mean, its damn near impossible to collect every weapon and armor in the game without a guide and that goes for most old school titles as well.

Really, you don't even need half the augments unless you want to take on the new optional bosses. I feel most games are design to be played more than once and experimented. Part of the joy I had playing through FFVI and Chrono Trigger is that I played those games so religiously I really did find elements that most needed a guide for. Hell, I've found equipment and items in both FFVII and Xenogears which no official guide even makes a mention of. I think guides are more of a deal thanks to GameFaqs and game stores always doing those package deals with new titles. If you ignore it, you can still game like its 1988