That was an excellent post, Spire, but I disagree for a few reasons.
First, time didn't become an element of Zelda at all until OoT. The overarching element of Zelda has always been exploration, and I think one of the most valid observations of Skyward Sword is that it takes away the Zelda-style exploration that has been the series' hallmark in favor of a more dungeon-like overworld. Whether that is to your tastes or not is a matter of personal opinion.
Second, I agree that the experimentation that characterized past Zelda games is gone now, and I would argue that's a very bad thing. Every console Zelda from the original through Wind Waker was something totally different and new, experimenting not only with gameplay, but also narrative, characterization, artistic style and everything else. Majora's Mask is a vastly different game than Ocarina, not because they changed the gameplay, but because they changed how the story was told; you can differentiate between any of the Zeldas before TP in the same manner.
Starting with Wind Waker though, Zelda has fallen into an almost cult-like obsession with the Hero of Time, and every console Zelda since then has tripped all over itself to allude back to him, whether it made sense or not. I actually give SS a pass on this point, as it seems conceived and designed to be a celebration of everything Zelda over the last 25 years. Since that seems to be its explicit purpose, I can't very well fault it for accomplishing that goal.
Like you said, I don't think it's a coincidence that Zelda has become less experimental (I would describe it in harsher terms, honestly) as the focus on continuity has increased; a continuity, mind you, that did not exist in LoZ-MM, despite all the attempts to retcon it into something otherwise. For this reason, I've started to actually consider the timeline to be an impediment to the development of the series. I honestly think that Wind Waker was a brilliant game, and one that archaeologists in hundreds or thousands of years will hold up as one of the canon works of our era of gaming. Unfortunately, it seems that WW will be the most radical departure from the classic Zelda formula that we'll get, because as Nintendo's insistence on tying together the games increases, the games seem to be heading into safer and safer territory (with the exception of the handheld games, which are still rife with experimentation).
For a counterexample, let's look at Final Fantasy. Yeah, there are valid arguments to be made about the series' quality as of late, but everyone has a favorite game, and we won't get into a discussion of which one is the best because that's besides the point (FINAL FANTASY VI). Basically, every FF is able to radically experiment with story and gameplay mechanics because all most of the games share is a name. Design choices in FF XIII were not dictated by story elements of FF XII, or any other one, so they could do whatever they wanted. Whether those choices were successful or not is once again a matter of personal taste, but Squeenix was free to make them. Zelda is now at a place where there MUST be a Temple of Time. There must be a lake, there must be a desert, there must be a volcano, etc. These things were all adventure game conventions too, but now they're also
narrative conventions, forced into the game to deliver a sense of series cohesion, and that hamstrings what you can do with said volcano, lake or whatever it is, because it has to make sense in the context of a game designed over ten years ago.
As another counterpoint: consider the Star Wars films. A friend of mine pointed out to me that George Lucas' increasingly ludicrous alterations of the Original Trilogy make alot of sense if you consider that he's going for aesthetic cohesion of the six-movie arc, despite the fact that the trilogies had 15 years between them. That's silly, of course: the movies already had narrative cohesion, so why is aesthetic cohesion necessary? It's not, but because he thinks it is, you get
this nonsense added to RotJ because Lucas put
this crap in Episode 3.
What does that have to do with Zelda? Well, I'm sure I'm not the only one, but I strongly believe that one of the reasons Skyward Sword takes place in the sky is to explain why the hell there's a floating continent in Twilight Princess that was never mentioned before. That decision informs most other gameplay decisions in SS, from the flying to the hub system to the way you enter the ground. That gameplay decision was motivated, at least in part in my opinion, to make sense of a past Zelda game. You may love flying, you may hate it. But you probably wouldn't be doing it if it weren't for the need to tie together la pretty major loose thread from TP. This necessity for cohesion mirrors Lucas' maddening quest, perhaps not in banality but certainly in purpose. And I think it hurts the series.
WAY TOO LONG, DIDN'T READ- The push to place 14 different games into a timeline is detrimental to the Zelda series in the long run. If Zelda has become controlled by the fans, I pray that those fans to give it back, because Nintendo's best efforts have always come from it not caring what anyone else had to say about its efforts. TP and SS (as fan-influenced games) are great games, but I consider them to be two of the weakest installments of the Zelda series, and they certainly can't hold a candle to the brilliance on display from LttP-WW. Both SS and TP feel trapped in the shadows of the Hero of Time, and the resulting timeline talk. Usually, "good-enough" is fine by me; not every game can be a masterpiece. But I expect and demand that from Zelda games, and I haven't had my mind truly blown by a Zelda game since Wind Waker. I want something bold, not just different; motion controls in the context of the Wii is not bold. Sinking Hyrule, setting a three day timer, those were bold moves, and I'm afraid Nintendo is now more concerned with shoehorning cohesion into Zelda than being experimental. As I said earlier, I don't think that the fact that my disenchantment with Zelda coincides with the rise of the timeline theorists is a coincidence.