Regarding both games: I think that some people tend to acknowledge the first title in a series more, because it did everything from the ground up. The same goes for Galaxy 1+2. Even if the second iterations of the games are better, the 'wow'-effect when playing their predecessors (which were built from the ground up) can be more striking.
Regarding Donkey Kong:
While I prefer Tropical Freeze, I think it's definitely going the 'more of the same' route than really setting the next step for the franchise. Things like more animal buddies or an interactive world map like in DKC3 could've really set it apart from Returns. It still has the best stages Retro has ever made and many of them are way better than what they've done with Returns.
I also personally think that the game is kind of anticlimactic after world 3. There are so many masterfully crafted stages in that world, followed by a still very good beach/world, but then it's a jungle-themed island again which I didn't really like and I'm also not the biggest fan of the snowy DK island, not to mention the boring bonus stages after the credits. If they would've managed to keep the quality steady after world 3/4, it would've easily been able to become the best 2D platformer ever. But it's hard to beat Returns, which had 8 (mostly) unique worlds with a continuously high quality.
Regarding 3D Land/World:
I believe that many people thought 3D Land was Nintendo's small handheld Mario experience and they would go back to the classic 3D Mario gameplay with the Wii U. Those beautiful looking streamlined (and very easy) levels are better suited for the handheld imo, and they don't really give you that adventurous feeling from galaxy or odyssey. I also think that the perspective can be weird sometimes, when you try to make precise jumps through rings or on enemies. The 'frontal attack' with cappy in Odyssey is definitely a result of the difficulty in 3D World, where precise attacks were not that easy to coordinate. In 3D Land you have the 3DS's stereoscopic effect and even when you turned it off, the levels are smaller and there's lesser stuff to do, which makes it actually easier to focus on your way to the flagpole.
I still absolutely love Tropical Freeze and I also enjoyed 3D world a lot, but I understand than some people prefer their predecessors.