A lot of what has been said targets the general philosophical problem of "is there such a thing as a factually good song vs. a factually bad song?" . I suppose the answer is no; everyone is of course entitled to his opinion. However, as members of the dT forum, our tastes most likely are similar in certain ways. For example, a song by Britney Spears or Creed can be factually "lackluster" on this forum. Though, I'm sure the members of the Spears and Creed forums would take issue with our saying that.
It's very hard for me to believe that a dT fan can honestly say that the quality of AROP is anywhere close to that of 99% of the band's other stuff. If you happen to like AROP, then that's your right, and so I guess your response to this thread should be "AROP is a perfectly good song, so DT would not see it as lackluster etc." But my guess would be that most of the people on here don't share the view.
So what makes the song "lackluster"? Well it's very hard to put a feeling into words, but somehow (and it's interesting) many people of this subgroup (dT fans) get a similar feeling. As was already said, the song's structure is predictable and generic. There is also no replay value in the track: I can listen to "Voices" ten times in a row and continue discovering new intricacies; if I were to listen to AROP twice in a row I would have to stop after the second go. There is nothing interesting about the chord progressions or notes being played. If instead of the first chorus, the band had decided to continue the song in a different direction, it probably would be a decent song, but instead, to the pitiful, cheesy sounding chorus. But the worst part of the song comes at 7:07 when the band's most awkward and rough transition can be heard (transition from instrumental section to the chorus). Basically everything a (usual!) dT fan looks for in a song is missing. I will say that the instrumental section is good, and there are some cool drum parts there. JP's solo is decent and JR's electronic sounds are very cool. Overall, it ranks in the bottom 1% of the band's catalog.