Nabeshin, I agree with you on that. Additional, I try to expect as little as possible from each new Zelda. But I won't deny that Nintendo occasionally drops the bomb at some points and leave some flaws. But like Yubel said, there are some personal aspects to it.
1) You get older and you interest changes a little, what seems cool when you younger looks average now. The earlier games often also come with the nostalgia of feelings.
2) The more games you play, the more you start to notice the things that keep returning. You start to focus more on that and less on the new stuff. And psychological the bad stuff and things that make you feel bad, everything you don't like, tend to remain fresher and more vivid in you memory.
3) Because you have seen and played many Zelda games, you have gotten some perfect image of the game. Each time a new Zelda is released, you started to think about this image and if it will be the next Zelda game. But once the next Zelda was revealed it didn't look anything like it and you got disappointed.
You will probably deny the above points, but subconsciously these things happened.
For a while now, I haven't really been playing Zelda games, aside from older ones. I feel like all of the originality has been sucked out of the series and they're mainly just releasing games for money, similarly to what's happened with Mario.
Sorry that I have to say this, but: DUH!!! Nintendo is still a company and the basis of the world they exist in has always been, is still and will always be about money. They aren't a charity case. It is pretty stupid to think that they would release any game just to make people happy. No cashflow, no existence. Simple really.
Minishcap, Four Swords, Freshly-Picked Tingle's Rosy Rupeeland, Phantom Hourglass and now Spirit Tracks have stolen the style born from that game and have compensated with only decent gameplay.
Not to mention that the Oracle games had the same style as Link's Awakening, which had a simplified version of ALttP style. A style which is converted to 3D in OOT. Since ALttP, Wind Waker was the only actual game that had a really refreshing style.
Twilight Princess has a nice atmosphere, yes, but it's one we've seen before. With the facelift graphics-wise, Nintendo must have thought it wise to copy everything they did with Ocarina of Time, it being their most successful game. Gameplay, battling, characters - it's all the same. I feel like I've seen pieces of Twilight's Hyrule in dozens of games.
Considering Dryland Hyrule has little changed since ALttP, and aspects were used in other lands as well; it is safe to say that you've seen it all before. And why TP looks a lot like OOT, is because millions of fans were bitching Nintendo about the Wind Waker, when it came out. Everyone was shouting "What happened to the Spaceworld 2001 demo? The part with Luigi made it to a game, why not Zelda?"; "This cartoony style is so childish, why isn't it more like OOT, that was cool!"; "We want a realistic looking Zelda!". Well, Nintendo listened to their fans and gave them a realistic looking Zelda in line with OOT. Now that Wind Waker is older and it's style of graphics has been used more it has become acceptable and even loved. But that wasn't the case when it came out. Millions screamed of how Wind Waker raped the Zelda franchise. (And it still got premier scores).
Zelda died for me the moment MM came out... The decision to emphasize strictly on character development instead of dungeon crawling took the series in a direction that was bound to be less impressive over the years.
That the games before MM where more aimed at the dungeon crawling than story development has a (techno)logical explanation.
What I am wondering about is why everyone keeps on whining. I agree that the Zelda franchise at the moment has a lot of room for improvement. But each game in the franchise has received premiere scores, that many other titles would commit murder for. There are a shitload of crappy games out there that are a whole lot worse than any Zelda title.
