The belief that someone who isn't a fan of the CoM battle system must suck at strategy is stupid.
I didn't hate it by any stretch of the imagination, but it is probably my least favorite KH battle system to date. It's back-and-forth tedium. It's a focus on numbers more so than it is on action. For instance, if a boss creates a sleight, you try to create a bigger sleight or use a zero card to break it. Does this require strategy and some thinking? Of course. But how does it not require strategy/thinking if you're trying to actually dodge a bosses attack rather than beat their attack with a bigger one?
More importantly, since when does "thinking" equate to enjoyment? And I'm using "thinking" loosely here. It's rudimentary math, folks. He puts out a 5 card, I put out a 6 or higher. Plus, much like the complaints about other games in the series, the system could be broken later in CoM. By earning enough CP to place cards in a 9-0-9-0-9-etc pattern, it essentially allows you to button mash to victory. By that, I mean, the bosses would try to break through your cards, and sometimes they would, but as long as you kept mashing A, you would break right through that. The AI couldn't do anything about it, they'd hardly ever fight back.
Additionally, battles were laboriously long. It took a while for you to die and it took a while for them to die. Even running into basic heartless felt like a chore later on. The length of the game was built too much on grinding and (in the case of room creation) backtracking. The rooms themselves felt at times suffocating.
As for story, lots of people say they love CoM, and then they forget that the majority of it (the Disney part) was complete crap. It was a rehash of KH1 with the contrived theme of memory forced into each world.
Despite all this, I don't hate Chain of Memories. I actually like Chain of Memories a lot. I just feel sometimes that people on this forum overrate it or don't understand complaints about it.
The reason why I like CoM is because I look at it differently than the main entries. It was built to be a side game (even if it is necessary to understanding KH2), and back when it was released, replaying the same worlds from a previous game wasn't a big deal. Before CoM, there was just KH1. CoM could be said to simultaneously expand on the story of KH1 with original content and recap KH1 with the "memories." And in sprite form, it felt like a novel enough change. Like, I don't look at CoM as being a full-fledged sequel to KH1 so much as it is trying to recapture that experience on a handheld, even though it technically is a direct sequel. It was also supposed to set us up for KH2, which I think it did rather well.
Even though I'm not much of a fan of the card system, I understand why it was used. The GBA couldn't handle many attacks at once (and it would look like a complete mess on the screen), so they needed a pseudo-turn based system while retaining a real time feel. So, CoM emulated KH1's system admirably enough. It also emulated the music well too, and the sprites looked great. I also enjoyed building decks for boss battles and random encounters (as I said, I'm not against "thinking"), and a lot of the sleights were very cool.
And lastly, yes, I did like the original story. When I first played, I felt like this was our first look at "Final Fantasy"-esque characters. It was cool seeing so many original characters with good interaction and a pretty engaging story.