Again, my main point is not playing someone else's songs, or not even a group just mailing it in, it is we, the people, after a 20 year career, do people really care about their new songs.
If the Stones come out with a new album, and go on tour, what percentage of the people who go to those concerts want to hear that new material vs Satisfaction or Sympathy of the Devil? U2 is touring now supporting a new album, how many people want to hear those songs vs Sunday Bloody Sunday or Streets Have No Name? Pearl Jam has a new album, but again, they do a great job with some covers on their own, but people want to hear Alive or Jeremy, etc...those are the songs that get the most reaction when played.
Maybe my term of "cover" is confusing. "Nostalgic" is what I am really going for. If Steve Perry got back together with Journey (hmmmm) and they put out a new album, I am sure it would do okay, but people my age don't buy much music anymore. If they go on tour, you know "Don't Stop Believing", "Faithfully", etc... those are going to be the crowd favorites.
And this is back to my point. You are an artist, and music is so emotional, unlike a writer or a painter, while it is in your DNA to create new works, likely the longer your body of work, the less people will positively react to that new work. And that must be frustrating.