It's far too slight and purposeless, in addition to lacking any quality music. Have you ever seen it or is this opinion based on the cast recording (which is missing much of the score and dialogue)? I performed the show almost 20 years ago and I still find it a complex rich and layered work. Not sure what you consider "quality music", but I find this score to be extraordinary, especially given the show's structure. His use of lyrics, lines and motifs linking the characters and situations across multiple scenes supports the central theme of Schnitzler's work and the subtlety to which he executes this prevents it from reaching Lloyd Webber laziness or gimmickry. Every scene, lyric and song is decidedly purposeful to the show's theme.
even if it _does_ only have two traditional songs in it I'd argue it has four: Tom, The One I Love, The Mistress of the Senator and The Bed Was Not My Own, if by "traditional" you mean songs that can be performed as stand-alone numbers outside the text.
"What can you expect from a bunch of seitan worshippers?" - Reginald Tresilian