In Style and Music: Theory, History and Ideology, Meyer has managed to articulate a pretty clear explanation of why I can't stand most Romantic music. One the one hand Romanticism was an ideology that rejected convention in favor of whatever was "natural" and ideally naïve genius. The problem, however, was that thanks to the consolidation of the tonal musical language that took place in the 19th century a thorough irony emerged--Romantic ideologues declared it was far better to invent a new process or idiom than to refine an existing one, and yet the Romantics spent the better part of a century finding new ways to play with a harmonic/melodic set of conventions inherited from the Baroque era on the one hand and the formal/procedural tools inherited from the Classic era. While lacking the truly revolutionary approaches to music that would emerge in the late Romantic/post-Romantic era, let alone the early modern period, the Romantics were already doomed to refine the ideals and options that were developed before them.
So even though Romanticism prized what Meyer called organicism (and that concept in the arts is really great, the ideal that a seed grows into a mature plant, a way of saying that ideas should be able to be expressed in the arts according to the nature of the idea), the movement was stuck. In his giant book mentioned at the top of the post, Meyer explained that what the Romantics ended up doing until Berlioz and Wagner introduced innovations in the fixed idea and the leitmotif, was basically disguising the conventions they relied upon rather than abandoning the tonal idiom they inherited from the 18th century innovators.
A crude way of saying what this meant is that the Romantic era composers couldn't improve upon French fries and wanted to not be like the people who came before them, but their chief innovation was not garlic fries or Cajun fries or any of that so much as that they just biggie-sized everything.
Meyer explained that the ideal for the Romantic was self-realization but the full realization of the self was impossible. A Christian teleological explanation for why this would be is that absent the eschaton, nobody's complete anyway. Romantic ideology may have simply transmuted progressive sanctification into what Meyer describes as the ideal of Becoming.
This would explain why so many Romantics created bloated pieces of music in which it seemed they never knew when to quit.
Now alert long-time readers could say "But Wenatchee, you like the early 19th century guitarist composers enough to write about them. And you seem to like some Romantics." Yep, fair points. Wenatchee likes some Romantic music. Guitarists were never able to engage in the biggie-size approach the way pianists and symphonists could during the 19th century. Twenty minutes might be starting up for some Romantic and post-Romantic composers, whereas for a guitarist a twenty-minute work might as well be for that guitarist what a Mahler symphony might be for a violinist. So there's that.
And when Wenatchee considers the Romantics he does like the names that tend to come up are Mendelssohn and Brahms. No surprise the sorts of Romantics with the most classicist tendencies show up, eh?
Meyer, over the years, pointed out that as the Romantics attenuated the syntax and forms they inherited from the Classic era they didn't just stretch things out, they also began to rely on what Meyer called a "statistical climax". For those of you not used to the jargon of musicology Wenatchee The Hatchet is going to borrow an analogy from another genre. If the Classic era had a Haydn finger-picking an acoustic guitar the Romantic era came to be dominated by a Pete Townshend pin-wheeling chords from his Gibson thundering through Marshall amps. That gives you an idea what a euphemism such as "statistical climax" entails at a practical level.
This has helped me get why I find a lot of Romantic music (not all of it) so insufferable. the Baroque and Classic era masters developed and consolidated forms and idioms within music that the Romantics by and large couldn't replace even though they had an ideology that more or less required them to repudiate the conventions they could not replace or particularly improve upon. So this explains why I love music from the Renaissance up to the high Classic period, and I love stuff from the post-Romantic Impressionists and the early 20th century avant garde. It also explains a little why I did American popular music (which, though it is thoroughly indebted to the harmonic vocabulary developed by the Romantics a century earlier, has had the good sense to know when to put down the guitars or usher in the fade-out). From this perhaps peculiar perspective, the Romantic era was less an era of actual innovation than a lame cul-de-sac in which composers substituted ramped up size for anything particularly daring in the way we think about music as an art form.
Fortunately folks like Debussy and Stravinsky found ways to shake free of the conventions that the majority of Romantics didn't manage to transcend.