Now lets put this slogan in perspective. You know that most people hate a certain thing with which they have a variety of strongly negative associations. And you propose to emancipate the very thing that they hate? As a public relations strategy this is no less doltish than it would be for gay rights advocates to employ 'emancipation of felonious sin' as the slogan which sums up the political, social, and moral aims of the gay rights movement!
Disastrous from the point of view of public relations, this much repeated slogan is also extremely annoying because it misrepresents and trivializes what I see as the most important goal of Schoenberg's compositional framework. This goal certainly was not to emancipate dissonance from its strictly functional role in tonal music and to make it "comprehensible" on its own, so to speak. Rather it was to emancipate melody and harmony from the constraints of their tonal straightjackets, and to make the enriched thematic and harmonic organization of non-tonal music as intuitively "comprehensible" to music lovers as that of tonal music.
If Schoenberg's chosen slogan did not sum up his project in this way, it is probably because he felt that even a dramatic enrichment of traditional methods of thematic and harmonic organization does not sound nearly as revolutionary as their wholesale replacement. Based on what I recall having read about Schoenberg's compositional habits (except for very late works), it seems to me that it was indeed the replacement rather than the enrichment of traditional methods that was his principal motivation, even if in his writings he often paid lip service to their continuing importance. He chose his tone rows so as to avoid (traditionally) consonant intervalic sequences and illusions of tonal centers. He generally insisted on using a single basic tone row for an entire composition - perhaps because obtaining thematic material from multiple rows, as opposed to deriving them rigorously from a single row, reminded him of the way subsidiary themes are introduced in tonal music. He even went as far as to admit having "an instinctive ... aversion to recalling even remotely the traditional chords". 
Alas, Schoenberg's replacement-oriented ambitions turned out to be far too tepid for the young radicals of the post-war avant-garde, as witnessed by the scornful dismissal of Schoenberg's legacy in the obituary written by Boulez. As for non-tonal composers closer in age to Schoenberg's generation, many had felt that Schoenberg's ambitions amounted to replacing one compositional straightjacket (tonality) with another (dogmatically inflexible serial organization of pitch). So these composers, beginning with Berg, took the enrichment approach to 12-tone composition, constructing tone rows containing major and/or minor triads (Berg's Violin Concerto), using multiple tone rows to increase the variety of thematic and harmonic materials (Berg's Lulu), and generally producing 12-tone works  in which allusions to tonal centers endowed the music's thematic and harmonic motion with a strong sense of directionality and emotional contrasts while avoiding the boring predictability of tonal music.
All this makes me think that if any composer of genius can be said to have fucked himself, Schoenberg must be at the top of the list. As a composer Schoenberg certainly had not done anything to deserve his peculiarly lonely place in music history: acknowledged only in passing by the later generation of modernists (who worshiped the more radical Webern), respected but not embraced by non-tonal composers among his peers (who either took Berg as their role model or developed their own more flexible 'personal adaptations' of the 12-tone system), and to this day still unloved by the general concert-going public. What did him in, I believe, were his much publicized misguided, dogmatic, and contentious pronouncements on music in general and his own music in particular. Like a classic case of bad publicity these pronouncements seem to have distorted the perception of the aesthetic aims and virtues of 12-tone music badly enough to create a lasting resistance not only to Schoenberg's own music, but to non-tonal music in general. Which is sad, but not surprising. What else would you expect when the most prominent advertising slogan for such music speaks not about the music's intoxicatingly enriched melodic and harmonic potential, but about its promise to emancipate dissonance and let it loose in the concert hall.
1. Arnold Schoenberg in his 1926 essay "Opinion or Insight?", reprinted in Style and Idea, U. California Press, 1984, pp.258 - 264.
2. Theory of Harmony, U. of California Press, 1978, p.420.
3. E.g., the symphonies of Benjamin Frankel, Ernst Krenek, Egon Wellesz, and Eduard Erdmann, to mention some (inexplicably neglected) examples of the enrichment approach which, as a listener, I find very rewarding.