Why, may I ask, do you beg to differ?
Ask anyone on the street to name you a "classical" composer (classical meaning anything dealing with Rachmaninov and earlier)....I bet you $10 that the first to be named will be Bach or Mozart, then Beethoven in a close third.
What does this imply? Well not too much for us Classical fanatics, however, we must consider the response from everyone, regardless if they hold a PHd in Music or only had one year of Music in primary school. The most named person will provide us an understanding on what the populus hears most. (The 3 mentioned above).
Now, what about MY personal opinion. Chopin is great, don't get me wrong, Nocturnes, waltzes, Scherzos, etc. But he died so young and his compositions so few when compared to more prolific composers and longer-lived composers. (Bach's compositions number in the hundreds, Liszt...hundreds, Mozart..hundreds) Their music to me is always fresh ebcause there is something new to me.
Bach is perhaps the greatest composer, ever. Even Chopin acknowledged this. Try to name a composer from the Baroque era without saying Bach. It's a lot harder. His impact of that era and of decades later were so huge.
I am sorry that this may seem a little "dumbed-down" but I cannot talk sophisticated about music theory and throw in the periodic musical jargon. I know little about it. I took it from an athestic stand point. More compositions keep the music fresh. Listen to Chopin's waltzes a few dozen times, they'll become stagnant because that intial swooning wears off.
I hope I made sense. But don't get me wrong, Chopin is great, but not the greatest.