I also looked at the other names on the list to see where I would put Schubert: somewhere between 25 and 30.
Schubert's fame rests largely on his song output. It's my own bias that songs are not very important musically. They actually are a mix of music and poetry (which does not count as music to my way of thinking). I probably do his chamber music an injustice, as I'm not partial to the genre. I'm not too familiar with his piano music. I see nothing special in his Impromptus. I like the Wanderer Fantasy, but it doesn't strike me as "great" in any way.
I rate composers after Bach on their orchestral output. I like Schubert's symphonies 2-6. They have charm, humor, good tunes, and are all classical in spirit. The 9th is much more romantic. I enjoy it, but find it "overblown" There was a time I didn't. I still have a problem believing Schubert could have written a symphony of such beauty and depth (the Unfinished) in 1822, at which time he had done nothing else of such note.
So, given my reluctance to admit he could have written such a gem, I have to rate him minus that composition. He still comes out pretty well in my book, maybe even generously in that he had little influence in music history except to create lieder. If not for Firebird, Petrushka, and Rite, I would consign Stravinsky to second string status.
The foregoing is designed to explain why I would not consider Schubert (minus the Unfinished) more than a "good" composer. He was born too early and died too soon to compete in the orchestral sweepstakes opened by Berlioz in the Fantastique. It is not intended to convince anybody else to bounce him from a top 10 or top 20 list.
With a modicum of humility, Shos

