I kind of feel like the talk about difficulty in Zelda is an argument that's really one-sided. Yes, to people familiar with Zelda logic, they've been easy for quite a while, but that's precisely because they're familiar with the mechanics. To people outside our hardcore Zelda/gaming forum bubble, they are still daunting, because they aren't as commonplace as the FPS genre's tropes. And considering the infrequent serialization of those tropes (a Zelda-like game comes along only every once and a while), they need to reintroduce the concepts and ease people into it with every title.
Could there be better difficulty options in Zelda? Yeah probably. But anybody asking for some true headscratcher puzzles or devious enemies have to realize that's not what Zelda is. Zelda is the quintessential Nintendo game: it presents you with a concept, iterates on it, and then twists that understanding in new ways. The fact that it isn't "challenging" represents that they presented the mechanics in a logical way that you could adapt to.
EDIT: Also this talk about TP saving the GC doesn't really strike me as true. I don't think Nintendo sees Zelda that way. They see it as a prestige series, the way Hollywood sees an Oscar film that may or may not make it big. That's why they give it a more flexible development than most of their other series.
