The difference is in the Nintendo Seal of Quality and the guaranteed attention to detail:
Dark Souls and Skyrim can´t be compared to Zelda, the series has been focused in puzzles for 20+ years, the first entry stopped being representative long time ago.
As for Mario...there are many great 2D platformers, but I haven´t played any 3D platformer that could be compared to Galaxy 1&2 or even to Mario 64 (though I may be biased on the last one).
- Darksiders 1 was great, but it had many rough edges.
- I love Okami, but pacing is HORRIBLE and the whole game feels like a tutorial. For all the hate Zelda games get for the hand holding it´s jarring to see Okami get a pass on it. Issun is FAR WORSE than Navi and Fi combined in this regard.
- Dark Siders 2 had progress stopping bugs that the devs couldn´t bother to solve, so if that´s all the respect you show your customers don´t expect that same customers to support your series for 30+ years like Zelda. For comparison, Nintendo asked players to send their savefiles so they could fix them when a game breaking bug was found in SS (which is something I found on the internet as I found no bugs whatsoever in my playthrough). Also the game was very unbalanced, once you got a weapon with the life stealing upgrade all challenge disappeared and some things like the blood gems/stones were crude examples of BAD design:
-Hey I had the best idea ever, let´s hide these collectibles all over the game!.
-Do we put them in meaningful locations, hide them intelligently, put them behind cool puzzles or use some kind of logic so the player can find them?
-Nah, just throw them around so the player just has to move the camera over every little corner of the world to find them.
Dark Souls and Skyrim can´t be compared to Zelda, the series has been focused in puzzles for 20+ years, the first entry stopped being representative long time ago.
As for Mario...there are many great 2D platformers, but I haven´t played any 3D platformer that could be compared to Galaxy 1&2 or even to Mario 64 (though I may be biased on the last one).