I'm not blowing anything out of proportion and while I'm not sure what "a fuzz" is in this context (that's a great term--do you mind me asking where you're from and whether it is common there?), I'm not trying to make one. And no doubt, my issue with the topic is less the main thrust of the initial question--would Wilson still be highly regarded if not for the Beach Boys?--than with the comparison to "classical" composers in general AND Mozart in particular.
So let me just make two (hopefully) quick final points on the subject to address the composer-in-general point and the Mozart-specific point, then I can be done with it.
1) Genius-Composer-In-General. This one just doesn't make much sense to me for a lot of reasons, for reasons made in my initial post on the subject. If we're talking about the music itself, Wilson's is just nowhere near as complex. That's not an insult. It's just true. Conversely, in the context of being appreciated by the composer's peers and sometimes the public, the comparison works, but it just doesn't seem especially noteworthy.
2) Mozart-Specific. Multi-part issue here--not with any posters on this board but the world in general.
a) Mozart being somewhat artificially raised to deific (I made up that word) heights and subsequently being used as some kind of ultimate comparison. If everyone understands it's more shorthand than reality, I guess it's fine (if lazy).
b) If we're talking in terms of the music itself, A v B (or rather WAM v BDW), they are similar in terms of popularity within their own (very different) contexts. BDW's probably was more innovative in its context than was WAM's. (I just realized I wish that my initials were WAM. I would insist people called me WAM, pronounced like wham. That would be f***ing awesome!) And as noted in my first post and general point above, in terms of direct comparison (as opposed to comparisons within their own contexts), BDW's is not even close in terms of complexity.
c) In terms of their talents separated from resulting music, I think a comparison holds less water: WAM was a true child prodigy in terms of both composition and performance, being trotted about Europe and amazing people; BDW could hum basic tunes at an early age and, eventually, painstakingly learned to transcribe music bar-by-bar, and later to write, arrange, produce, etc. very well.
d) If we're talking personalities or lives, which is a big part of what I always suspect drives the comparison ("troubled genius," among the most tired stereotypes there is, in my opinion), the biggest similarity is just a broad storyline of "child star gone wrong." Again, it's such a common storyline it doesn't seem worth mentioning. You could make it more specific by adding "parent of child star a big part of the problem." Remains common storyline among child stars gone wrong. The specifics of their issues are quite different, so I don't know that you can take it that much further. Mozart remained a hard worker throughout his life, Wilson took breaks. Mozart remained a public figure, Wilson kept out of sight for periods. They share a sense of humor, though Mozart's tended to be toward sh*t-jokes... (Classy guy.) And I'm not sure Mozart had real mental health issues (prior to whatever his final illness led to, which isn't really the same thing), though it would be tough to say considering the lack of understanding of them.
And finally--yes, I said this would be short and halfheartedly apologize that it wasn't--to the real point of the question: would BDW be held in high regard as a musical figure if not for the Beach Boys? Probably not; it's unlikely he would have been known well enough to have been appreciated, though it's possible he could have gotten a gig as a staff songwriter and producer at some point and gotten into the industry through that route.
Hey Luther, I was by no means referring to you with my last post. It was just a comment to the reaction the name Mozart generated in this thread.
I thought it was interesting the idea to (somehow) draw comparisons between Brian and such a historical figure. You made some really good points, specially the difference between their work dedication throughout the years and their personality.
But again (and I think we agree) both artists live(d) in different contexts and a straight comparison is neither possible nor desirable.
Just one last comment. Mozart wrote music, he performed it when alive, but we don't have any recordings (for obvious reasons). The greatness of his oeuvre comes from how famous Directors & Orchestras have arranged and performed his work over time. So in a way for us Mozart (or any other great composer from his time) is a genius because other great musicians have made him one. If the only example of his work were recordings of performances from a bad, lousy orchestra, I doubt he would have the same general appreciation.
Likewise when Brian broke free in his musical production from the limitations of the band (as musical performers, not vocalists), he was regarded a genius. True, there was a marketing campaign behind it, but anyone with 2 ears (or even one

) would agree after listening to the tag to 'God Only Knows'.
Can you imagine 100 years from now a top orchestra performing 'Pet Sounds' as a symphony? And then image the public then not knowing the original recordings from the BBs. I'm almost certain that they wouldn't find the comparison between BDW and WAM so out of place.
Again, it all depends in the context

P.S.
- I agree, WAM sounds a mofo of a name!
- I'm from crazy Montreal, where are you from?