Ugh...do I really have to go into detail as to why I find Skyward Sword dull and lazy? So many words...
My biggest problem with Skyward Sword is that to me the Zelda series has always been about 2 things: exploration and discovery. There's the thrill of knowing that if you wandered in a certain direction or explored that conspicuously-looking part of the world, you might find something interesting. Maybe it's a heart piece, maybe it's a chest of rupees, and maybe it's just a grotto with some fish swimming in a pool. Regardless of what I found, I was always excited at the thrill of the hunt for secrets and new areas.
Skyward Sword doesn't have that. There is nowhere to explore and nothing to find, because the areas are ridiculously small and nothing is truly hidden. Instead, the "secrets" are often walled-off in plain sight behind metaphorical doors that require keys often shaped like hookshots or swimming fins. The developers call these "puzzles", but what kind of "puzzles" rely on one-step solutions? There's no thought, experimentation, or exploration involved in solving these "puzzles". It's just a question of whether you have the required item or you don't, which would be alright if these "puzzles" were actually hidden. But they aren't. They're right out in the open, so there's no sense of satisfaction when you "solve" them, just a sense that you're checking another item off your scavenger hunt.
Also, it seems to me that the developers designed Skyward Sword's areas to be small and compact as they are in reaction to the complaints about the wide open fields/seas of nothingness in Twilight Princess and Wind Waker. Here's the problem, though: the huge, empty Hyrule Field wasn't removed. They just threw it up into the clouds, gave you even less reason to explore (because there's nothing to find in the skies unless you've unlocked it down below by hitting a Goddess Cube, and even then they're not hidden and often require a tool-shaped key to reach), and renamed it Skyloft. Instead of solving the problem, they merely re-named it and gave it less emphasis. The Overworld in Twilight Princess was too big and dull to traverse, but at least there were things to find in it, which is more than I can say for Skyward Sword's Skyloft Overworld.
Another problem of the developers' "all 'puzzles', all the time" approach to the world design is that it ignores the reason why the dungeons were compelling in previous Zeldas: BECAUSE they were a departure from the rest of the game, a change of pace. Instead of roaming around Hyrule Field as you pleased killing monsters, you were in a more directed, puzzle-driven experience. The two halves complemented each other. By the time you got tired of free-roaming action, you were going into a puzzle-driven dungeon. By the time you got sick of solving puzzles, you were back out in the field. That distinction is gone, now, and the constant "puzzles" got tiresome for me.
There's also at least one major missed opportunity/laziness I've seen in the game, but it's a major spoiler: late in the game, you discover a way to travel "back in time" to the end of the major war that kicked off the events of Skyward Sword. But all the portal leads to is...a nearly identical version of the room you were already in, with the characters merely telling you it's the Past now. It's the Underwater Hyrule from Wind Waker all over again, where we could have been treated to some really interesting places to explore and see but the developers do not let the player do so. In Wind Waker, I can accept that as a relic of the game's rushed development, which also struck two more potential dungeons from the game. But Skyward Sword had all the time in the world. It's sheer laziness here.
There is also the ludicrous amount of lazy padding Nintendo put into the game to stretch a 20 hour game into a 60-70 hour game, but I trust I don't need to elaborate on that? I have gone into this in significant detail in the Skyward Sword thread, as has Radio Free Nintendo the last few weeks.