OK, now I'll really tell you why I think UF is U2's worst album.
A) Filler. Almost half the album is pure filler:
4th Of July (Come on, do I really need to say why this is filler?)
Elvis Presley And America (Just ASOH played backwards and slowed down with crappy lyrics over the top :shrug)
Indian Summer Sky (Has no melody. It just sounds like a really, really, really bad War b-side to me)
MLK (Pretty obvious filler as well)
B) Bono has little control over his voice. He spends Bad just singing like he's still in puberty. Voice cracks and all. It sounds vulnerable, but compare it to the brilliant WAIA version, and it's left as useless. He sounds awful on ISS and EPAA too.
C) What does that leave in successful songs?
The whole first half.
And that is all.