I dunno, it's just so many aspects about it's creation are not exactly typical for DT. It was made for dramatic effect for a sound track for a videogame. Sure it's a song. It does have a weird structure though that reflects various themes intended to create different atmospheres, almost like a game developer could pick and choose which section creates the appropriate mood theatrically for whatever cutscene or environment the section is used in. Not to mention the song is written to be an infinite loop.
I think with some of these things in mind, the band's intent was very different to almost anything else they've written. To answer your question, I'm not saying it shouldn't be compared to other songs, I'm just saying it's so different from the ground up and doesn't really work as well as a stand alone song as it does within the context of what it was written for. So I just find the comparison a bit partial because you could say it's getting relatively judged, slightly out of context. Nothing wrong with comparing things on their own, it's just more an observation regarding these comparisons to other instrumentals or songs.