U2 fans were having a fit when the saw the first setlists on the new tour because the band left off the "hit" songs and pulled out some catalog songs. Every successful long time band has this problem. Hard core fans want deep album cuts that they never saw live, rocker fans don't want any song played that doesn't have at least a two minute guitar solo, ballad and love song fans want all of those songs played and casual fans want the "hits', the singles that they know.
i'm sure there are nights when JBJ and the guys would like to come out and play just their favorites but it probably wouldn't make for a good flowing show and they are there to entertain other people not themselves . It's a guessing game I think, trying to pull from the catalog. I think you have to take the new material and pull what fits best from your catalog, the songs that flow best and go for it. I think Bj does it better than most they do change up some and JBJ has been known to add or change something right on stage either because he saw a request or because he was just in the mood.