I don't know, there's been a lot of posts saying "there is no pretentious music. There's only fan bias, or pretentious artists, or etc. etc.".
You can try to argue away things with superficially good-sounding arguments, but I think everybody has at least had once the gut feeling upon listening "ugh jeez, that is so pretentious".
Music is an expression of the artist. If the artist himself is pretentious, very likely will the music reflect that. Yes, Einstein, music is not a human being and thus isn't directly pretentious, but when people say a song or album is pretentious, they're clearly talking about the artist's pretentiousness having been imprinted onto the song.
And of course, prog is the master of pretentiousness. Prog almost defines itself as "music as big a piece as the artist can swallow", but in more cases than not the artist just stuffed his mouth full of Twinkies, in the hope nobody will notice.
There's few prog artists who really can fill the shoes of the lyrics they're attempting to write. Neil Peart is one of them IMHO. DT luckily stays away from it, partly probably because none of the guys even think about those big topics.
rumborak