In a nutshell, the argument is that U2 were on the top until 1990, and have started declining ever since. They've allegedly reached the final stage now: irrelevance.
Obviously U2 now are not U2 in 1992/93 (if anything, I would have said that that the very top was back then). Yet I wouldn't say that NLOTH is irrelevant. I think it is better than ATYCLB and HTDAAB: you can listen it to it from the beginning to the end and then start listening again. Many times...
Bands must be judged by the music they make. U2's music today is still great, so they're still such a great band. People like Sterdan seem to miss this very simple but fundamental point.