(Please not that this is solely my OPINION)
I thought Spirit Tracks was good. I just don't get why people don't like it:hmm: (Spoilers!)
Well, the music was great, especially the Link and Zelda duet. It wasn't like Phantom Hourglass, where there's only one dungeon theme, one island theme, ect.
The puzzles, I swear, stumped me a few times, that I had to look it up in the walkthrough. (And I don't do that often, unless it's Twilight Princess)
The overworld was... empty. You could only exit the train into the overworld only a few times, and I really missed traveling on foot. It's one of the flaws in this game, but traveling and "seeing the world" is one of the good qualities of a Zelda game.
The plot had a ton of twist and turns, which important, in my opinion. (The plot gives us writers an open opportunity to write, and some fan fiction in the fan works area is based in Spirit Tracks.) No way we could've predicted that Bryne would join Link, Zelda and Anjean later in the story! Or Malladus the final boss, instead of Cole.
I'm only going to make an exception on graphics, since it's a DS game. The graphics aren't really what I prefer, so I'm not going to rate that part.
But overall, this is a pretty good game. I get why people don't like it, now. But why do you think it's a bad game, solely on the overworld part? There are other good aspects of the game! Why not concentrate on those?