I personally love this score, a lot. Yes, it can be downright bizarre and strange in many places, but on the whole it is a very creative, well-executed score that impeccably suits the similarly wacky nature of the game to a T and beyond. as for whether it is enjoyable on its own, that's a matter of perspective.
Personally, I loved the Runaway Five tracks, most of the battle themes, every town theme, the "Demon's Wall" fight cue (which starts out 8-bit then goes into a groovy rock-and-roll fest), and the songs that play both at the epilogue (the rest of the cues during the final battle itself are downright strange and almost cacophonic --although effective in its function--, especially the final moment when Giygas "dies", via TV static) and the final closing credits.
The latter, in particular, is arguably one of the score's best highlights: it reprises all the town themes and arranges them into a "concert" suite style, albeit in a pop-rock style. The "Smiles and Tears" song is a glorious extension of the "Eight Melodies" song; its slow, jazzy style provides for a nice send off. (The utterance of "I Miss You" just before the song's final stanza always struck me as eccentric, but no more so than the game itself.)
So all in all, this score is a "Your Mileage May Vary" thing, and can be rightfully called an "oddity", which it acknowledgingly is, but I personally liked it a lot. Pity it's never been released in its entirety, as there are a lot of cool songs on there that really deserve better exposure. The original "Image Album" release of MOTHER 2 didn't really do the music much justice.
I agree that it stinks that NoA didn't release this on VC, but the fact that it was only a "rights" issue is at least a bit more "understandable" than the rather ambiguous "repsonse" they left for the much requested Wii RPGs -- Xenoblade and The Last Story, resepectively. That said, Operation Rainfall is working very hard to change the situation for both of these two, and as a personal member of the movement, I couldn't be any more proud of what we're doing to fight for them.