I would believe they've improved over time. But my comment wasn't that pandora had a poor catalog. It was that they wanted to play mainstream songs instead. Perhaps not even mainstream, but just very specific songs. They had a lot of artist's whole discographies but only a subset would ever come on. I can still remember a few of them for me:

royksopp - this must be it

trapt - headstrong

ladytron - destroy everything you touch

Some sort of remix of the hand that feeds by Nine Inch Nails (I think it was the photek remix or something)

I got these songs a lot on many stations, and nothing else by those artists ever, haha.

I don't hold a grudge from 10 years ago though