Bourne is well past it's expiration date and yet...
As always, an IP does not need to be hot to be theme park worthy. It needs to either be nostalgic (which Shrek absolutely is) or have a world in the movie worth building (which Shrek has). This also applies to Avatar. Most people are not giant flag waving Avatar fans, however, it was a great theme park candidate due to it's world. Disney didn't exactly do it perfect, but the point is an IP doesn't need to be hot to be worth a theme park spot.