Ok. So I realized why I liked this game now and not before. It was surprisingly complicated.
The first thing is that I had just finished watching the anime when I first picked the game. I don't like moe (or rather what I find moe is completely different than "normal" moe), and I had forced myself into a pretty boring marathon. I was sick and tired of all those characters, which downplayed the management factor for me (god and yuki know that I really like management games, and while I wouldn't say it's the main focus of this one [may be wrong though], it's still a relevant one) and I'd just rather play osu if it were for the songs.
The second point which made me dislike it in the past is that, well, I was already sick of rhythm games anyway. I'd rather play osu, but I didn't even want to play osu. Since I was in my house, with the perfect atmosphere and the knowledge no one would bother me, I'd just rather play some VNs like I always do.
right now, I am traveling and bringing my pc is unrealistic. Even if I could, I wouldn't play a VN in a noisy place full of people, I wouldn't be able to fully concentrate (or a calm one where I'm prone to sliding off some rocks) Since I'm visiting lots of places, I had several half-hour breaks with a few hours of activity following those, which just made my schedule perfect for the game.
The "Ah, all these characters are annoying me" feeling is gone too, since enough time passed since I watched the anime, which made card-collecting pleasant (no one wants to collect cards of things that annoy them, I'm sure).
Hm. That's mostly it. Mystery solved. I'll probably keep playing this for another month or so. Until then, yay, my post count will raise here too. Everyone, treat me nicely~