I think the problem with some performers is, they are known for a narrow slice of pop culture, and that's what people who go to see them expect to see. I would venture a guess that there are many who go to her show that can only identify "Downtown" - and that's all they want to see.
That's why people who have many years of many hits are so invigorating - quite a catalogue to pick from (Elton comes to mind.)
I'm glad you enjoyed the show, though. At least now you know you won't have to go see her again