For a band that is so good and who generally know how to tell the difference between good songs from the bad ones, I don't know why they do this. They have done it right throughout their career as well. See Red Light, Elvis Presley, Trip Through Your Wires, Some Days, Daddy's Gonna Pay etc. Achtung Baby and Boy are probably the only two albums of theirs that does not have any clunkers on them. It's as though they deliberately go out to sabotage their own work for whatever unknown reason.
You see, I think this is a silly comment. All of the songs you mention are the worst on their albums (subjectively - except Daddy’s Gonna Pay, as you already mentioned Some Days). But they all have a purpose and link to the album as a whole.
Masterpieces don’t come along easily, and something has to be the worst on an album. With the songs you’ve mentioned, they may not be up to the incredibly high standards of the rest of those albums, but they at least seem to stem from the tone of the album.
Contrast this to, say, SUC, and there is a real disparity. Simplistic music, inane lyrics, and totally unsuitable for the rest of the album. I think it is fairer to criticise the band for latter-day ‘laziness’ of a song like that, than creative missteps like Red Light, Elvis Presley & America, Trip Through Your Wires and Some Days Are Better Than Others.
U2 aren’t perfect - but I’m not going to hold how close they have come to perfection on a regular basis over a 40 year career against them, certainly not in the case of a handful of not-great songs.
I’d take them over complacency any day.