U2 did meet him and they decided that they liked his approach. This was the beginning of some very high profile production work for him. Word was out that Daniel Lanois was an excellent producer and people wanted to work with him. Peter had a bunch of multitracks that he wanted to rework for the soundtrack and thought that Lanois would be the best person to help him remix them and put them in the new context. Lanois felt that no one had really been able to capture the energy of their live performances and felt that he could offer them the focus and direction that they needed.
Record production is about results.
Someone could walk in with a song on the acoustic guitar. You shouldn't let them overkill it. Maybe it wouldn't be right on an acoustic. Maybe it needs a beat or turbulence. It's about having some kind of idea about the potential of something.