I'm with you.
The biggest complaint I had, with the original and remake, is the gameplay. People can voice their opinion about how innovative it is, but the fact of the matter is that innovation doesn't always equate to fun. It was a noble effort on the GBA, to be sure, and they spruced it up nicely on the PS2 but, regardless, it's not my kind of gameplay, not the kind I grew to love about KH1 and KH2.
Room creation is, again, a nice idea, but it creates a sense of discontinuity between areas where you're just boxed in from one room to the next. Changing the battlefield also seems to upset the continuity between the story and the actual combat. Does Sora actually transport to a circular arena for Org fights (rhetorical)? The setting change is too final fantasy.
The cards themselves created an extremely disjointed back and forth pace that seemed ultimately more irritating (especially in sluggish battles like with Repliku IV) than thrilling. I didn't feel satisfied when I destroyed a boss or set of enemies, I felt relieved that I could finally advance... and do the same thing later.
Not to mention how the randomness of the room creation cards totally sapped the fun out of exploration. How many times did you continually fight hordes of the same enemy until you found that Green five card? I sure as hell did it a lot, only adding to my frustration. In fact, the whole concept of exploration in this game was nothing more than grinding, making the pace even messier than the battles.
Now as for plot... it was good. Nothing outstanding though, it's much more mediocre in my eyes than many see it. It is, well, a very fitting side game.
The individual Diisney plots were terrible. Rehashes of the original KH Disney plots, except convoluted and warped by the theme of "memory" crammed in. The plot drives the Disney characters, whereas a good game should be vice versa (characters create the plot). There was nothing to look forward to in the Disney areas, same enemies, same-styled plot, same characters, same bosses, same places. I don't know about you, but every time I advanced to the next floor, I was anticipating getting out of that world to see Castle Oblivion's plot.
The Organization plot was clearly the highlight of the game, the one thing it did unquestionably great. Even then, though, I wouldn't commend it as so much better than, say, the main plot of KH2 as many others do. They took a different approach, that's all. CoM had the Org members in a much more down-to-Earth scenario where a damsel was in distress and the hero thus needed to make contact with them in order to advance the story. It allows for a more recognizable enemy, which is why they had some leeway in creating the conflict between the individual Org members. KH2 had the Org members in a more elusive and enigmatic manner, one that echoes back to the antics of the Disney villains in KH1. While this doesn't allow the character "development" that people lament about KH2 lacking for the Org, it wasn't needed, at least back then. Only in retrospect, when looking at CoM, did people want to know more about the Org interactions. Before they were simply supposed to be that far off, unknown enemy. Now we've got Days coming out to fill in that development.
Anyway, before I go off on any more tangents, CoM was a great addition to the KH series, and a welcome one at that. I find it as ludicrous as you that so many people praise it to the extent that it is the best game. In all honesty, the only explanation I can offer is that they look too much past its mistakes (since it was originally on the GBA) and delve into subtleties of the plot (looking too hard). The fact of the matter is that, if CoM were to be summed up in a few words, "side story," "rehash," and "grinding" would suit it well.
I do like RE:COM though...
