Being in high school on the west coast of the US during the 90s, I lived through that grunge / alternative period.
In the US, so much had to do with timing, luck, and what was goin on in the world. Grunge had some impact on modern rock / new wave, which is the type of radio stations in the US that were playing U2, INXS, REM, The Cure, Depeche Mode etc. The tail end of the 80s we had music in that genre that was already starting to change, and it was even less define-able. Red Hot Chili Peppers, Faith No More, Jane's Addiction, Jesus and Mary Chain, and Pixies all released songs/albums that were huge in that time. Madchester was also in heavy rotation in the US at this time.
Grunge / Alternative hit. It's impact was greatest on Hair Metal. Suddenly all the hair metal bands died away and became uncool. Some of them attempted to become more "grungy" but that didn't really work. U2's Achtung Baby came right at the transition. Grunge did not quite have the label yet. My friends who liked "harder" music leaning more towards heavy alternative and metal (Meat Puppets, Nirvana, Metallica, Anthrax, Alice in Chains, Sound Garden etc) were turned off immediately by Achtung Baby, giving away all their U2 albums. To them it was betrayal. The Berlin Wall coming down, and the changes in Europe had a lasting impact. So did the first Iraq war, CNN coverage, and the US presidential elections.
U2 and INXS were considered dance-able rock. INXS was always in this realm. Outside of Two Hearts Beat As One, and remixes, U2 were never really played on the dance floor, and the band were not seen in that light. They were also seen as firmly planted in the rock area (outside of the club). So this was new for U2. Yet they came out with an album that clearly showed a change on every single level - tone, vocals, musical style, aesthetic etc. Every single aspect of the band and album was different. INXS to the US audience was basically the same. U2 played a part in politics, calling the White House leading up to the election, to enormous crowds. ZooTV was commenting on CNN and media overload even before Fox and MSNBC came into the picture. The timing was perfect. AB was dark enough to not be seen as lightweight or even Madchester (despite taking questions from that area) by some of the more rock-oriented scenesters, but they were so much different from the grunge / alternative scene. They stood out. This was refreshing to most people who were not walled into a rigid music scene (which was very common and segregated in those days) There were also those who fully understood, that the dressed down aesthetic of grunge U2 had already done.
So you have INXS who are seen as doing very much the same thing they've always done (just slight variation), both in music and in image. Then you have U2 who were seen as drastically changing, but not changing WITH the most popular zeitgeist of the time. They were changing in stark contrast to grunge and alternative, but changing right along side it, doing their own thing. While U2 have made other changes, due to timing and type of change, none had anywhere near the same level of impact.
