Why And When Did U2 Lose Their Heart For Music?

I am a huge fan of the band. Have been ever since I picked up a
cassette copy of War way back in 84. But, like it or not, after a run
of brilliant albums (Boy, War, Joshua Tree) there was a huge falloff
in the quality of their music starting with Achtung Baby, which in and
of itself wasn't a bad album, but it sure wasn't as great as War, or
even The Unforgettable Fire. And since Zooropa? They've been mostly
awful.

What do you think happened?

BQ: U2, Yay or Nay?
BQ2: Favorite U2 member, album and song?
BQ3: Is Bono a jerk? Yay or Nay? And if he is, do this color your
outlook on U2?