They have just made it harder. They've abandoned the true 'God walking through the room' magic of the way they used to make records. They'd jam and accidentally just stumble into something incredible.
Just some accumulation of my thinking based on what I've learned about the band. Turns out this kinda long. Forgive me.
The band is in a similar state as they were in 1990, except even worse.
ATYCLB and HTDAAB were a huge force in the charts and radioplay, but as soon as they got comfortable and decided to make NLOTH just for kicks, they were then disappointed. Remember NLOTH was a collection of songs that wasn't initially planned to be ever released. The band thought they had great songs, but they turned out to be highly irrelevant to listeners in 2009.
What they thought was interesting and cool in Morocco was not anywhere interesting for the audience back home. It's kind of like Rattle and Hum. U2 wanted to show America its roots, but America was like OK...that's cool for you...but kind of boring for us. In 2008-2009, they though they could progress their sound by bringing in some Northern African elements, which they found interesting, but the mainstream audience doesn't really care what inspiration you find for your sound. They just want exciting sounds.
It's not really anybody's fault, but the whole method of just going into the studio to just jam out songs didn't work for them. Why should it work for them now?
The band has gone for almost TEN years without a radio hit. That is a LONG time. The stretched out world tours of Vertigo and 360 (lengthened by illness and injury), plus the long recording time of NLOTH, has no doubt killed their relevance. Think about what has changed in the music scene since 2004. The teenagers of today were toddlers. They grown up listening to manufactured pop music or a crummy indie scene, or even worse...dubstep. What did the teenagers of 2004 grow up listening to? A much more diverse set of music of the 1990s. Since then rock n' roll in general had died in the mainstream. It was dying after the exhausting 1990s, but fortunately U2 benefited from a short garage-rock revival in from 2003-2005. The mainstream audience has moved on, and U2 has unfortunately fallen way behind.
U2 recognizes this. The odds are stacked against them. They are in their 50s, and that makes them super uncool from the get-go. They are great musicians, but it doesn't make a damn difference if they can't connect with today's audience. I can only think they are in the studio trying to not only integrate back into airplay, but also "fuck up the mainstream". Because that is really what U2 is best at. Their albums are never truly mainstream, but are fresh enough to captivate listeners.
I constantly see people comment "why should U2 even care about radio hits?" My answer is: Probably because they are still trying to challenge themselves. They've shown they can release great music with NLOTH. But without a strong hook, those are just songs. It doesn't excite your friends. Music that hooks listeners beyond your core audience and gets people talking is U2's definition of success.
I quote Bono's last line in From the Sky Down: "You have to reject one expression of the band first before you get to the next expression, and in between you have
nothing. You have to risk it all."
U2 is trying to start afresh. They have nothing at the moment. They are just trying to find the songs. I wish the band never released Ordinary Love and Invisible, because people automatically assume that these are going to be the best U2 can put out. The band is just testing the waters. The lackluster response to Invisible is probably an indicator as "Hey, we still have more work to do. We just don't quite have it yet." It's very important that they get this right. Because....
This next album is IT. It's success will probably determine the fate of U2. If they can't be successful in their mind, then what is the point of continuing on? They've always said it. We don't want to be the Stones, but we will keep releasing music if it keeps you and us interested. This next album is the hardest album they are going to write. I prefer they take their time with it. Because I don't want U2 to retire.