ATYCLB, HTDAAB and their respective tours, grammy awards, super bowl performances, etc... cemented U2's legacy forever. After the Vertigo tour, I think they should have "retired" from the game of trying to make HITS, and just focused on making good, uncompromised music. Just put out new music whenever, and tour whenever. Release new music with Danger Mouse, Ryan Tedder, RedOne, Rick Rubin, etc. Go to Fez with Danny and Brian, and make the truly interesting album NLOTH almost was, before it was compromised. Hell, it could've been a Passengers vol. 2. Open the vaults. Collaborate with other artists. Make soundtrack songs. Be in a state of regularly releasing new material just because, instead of releasing a new album every 5 years after numerous delays and rewrites.
Another idea... go back to September 2014, and think "hey, instead of pushing this album onto all of Apple's devices, let's just offer everyone a free download if they choose to want it". Turns an extremely negative thing into an extremely positive thing. Public perception of U2 and SOI does a complete 180.