I wouldn't say that not remembering a score or even vaguely being impressed by one is necessarily a negative factor for the final judgement on a film. But surely, when I like a music, or at least it is well-made, I usually remember at least the refrain. It just didn't happen this time.
Actually, I haven't seen this film, so I'm speaking only theoretically.
I didn't mean that one should remember the score. I also don't (like with score to Akahige, which is wonderful, but was replaced in my head by another piece of music, which is a bit similar and which I know for years.)
Remembering the score after the first hearing usually means for me it's quite crap, made only to be remembered... not everytime, but such songs you have to remember and that stay in your head for days are really terrible.