Rachmaninoff is quoted as saying that he thought "The Bells" to be his finest work (although he probably said that long before he composed the Symphonic Dances and you have to wonder). It certainly belongs on Symphony Hall.
The only question is why it is compared to Beethoven's NInth, an early romantic symphony with one choral movement.
A much earlier and much more comparable full-length secular choral setting of a lengthy poem, with orchestra is Haydn's "The Seasons. In fact, it shares the same quirk of starting out as a poem in English, being translated to the composer's tongue, then set to music, and often now sung in English in a translation of the translation, instead of the original English language poem.