It's fascinating that Tchaikovsky is "too Disney-ish", considering the composer died a full eight years before Walter Elias Disney was born. Perhaps if you contended that Disney was too Tchaikovsky-ish, your prejudice would gain greater validity. But Disney was less a composer than a cartoonist, and Tchaikovsky much more a composer than ever a cartoonist. I would also contend that Tchaikovsky was much more of a composer than ever was Disney as a cartoonist. But this is rather like comparing apples and oranges, or Russian ballet and mice.
Which might reveal a prejudice I have for a certain Russian composer.
Few composers move my heart in the way Tchaikovsky can. The Sixth Symphony (seeming to me a rewriting of Beethoven's triumphal Fifth) remains as stunning a portrait about wrestling with destiny, a destiny which crushes the protagonist and leaves him shattered and devastated, as was ever devised in art. It plumbs emotional heights and depths which Disney, at his most creative, could only glance at.
Yet, this same composer gave us the joyous Nutcracker and the Capriccio Italien, two phenomenal piano concerti and a to-die-for violin concerto. If I find any shortcomings in Tchaikovsky's work, I rather chalk them up to my own lack of understanding. My prejudice for Pyotr Ilyich includes giving him the benefit of the doubt.
If I have prejudices towards the negative concerning music -- that is, prejudices towards music I don't like, I would name rap, hip-hop, and much minimalism. But I'm not so closed minded to not be prepared to listen to fostering arguments for these genres as music, should there be one out there who can eloquently make the case. I'm all ears.