I think you've done a good job of getting to the meat of the issue in the U.S. (incidentally I see you're in Dallas, I saw POPmart at the Cotton Bowl with RATM. Horrid venue for a concert).
Discotheque wasn't the problem (they could have survived that video if not for the insincere tour itself). Bono just like to say Discotheque was the problem (and he is attempting to do the same with Boots and NLOTH).
And that's why this issue with POP/POPmart is still relevant. As long as U2 remain deluded about their revisionist history with POP and POPmart, they won't be able to truly move forward and be the best they can be.
And that's the issue. How it affects U2's future music/tours. Every creative step since 1997/98 has been marred by the cloud of POP and POPmart. Until U2 understand that it was the insincerity that people rejected, they are libel to make some of the same 'bloated' mistakes over and over again. Meanwhile, they are so fixated on "hits" Bono can't even see that Discotheque was a big hit in and of itself.
I mean, really...the whole last decade and a half has been relative to the so called failure and mistake of POP and POPmart.
I think U2 need to find those kind of balls again, or they might not want to continue as is. Until they can be comfortable enough with that kind of risk (in the music) I don't know if it can happen.
Any and all POP fears they might have had were firmly dealt with in the mega sucess of ATYCLB/Elevation.
Discotheque may have been a top 10 US hit, it didn't sell the album like BD or Vertigo did. The folk didn't respond to Pop the way they did with Bomb or ATYCLB. Similarly, Boots didn't sell NLOTH and I don't think the people warmed up to the album. Certainly the band dropped several songs live (while that happens on most tours, not to the extent NLOTH suffered).