It hasn't, though. Larry Ellison has shown time and time again that Oracle is just about the bottom dollar. SCO was just a patent troll, but in Ellison's Oracle, patent trolling/litigation is just another "wing" of the business of making big bucks. Oracle did the math and thought it would be worth the risk/investment of taking this all the way in anticipation of a possible payout on the scale of billions of dollars, and it didn't pan out. That's what makes this all the more annoying: this isn't their core business model, they're not SCO, but they choose to pursue this anyway.
I don't think you know much about Oracle. Aggressively defending their assets through the courts is something Oracle has a long, long history of. Sometimes they win. Sometimes they lose. But they almost never just let things slide.
Pretty sure Larry is wearing his kimono with swords by his side when he's making the decision to "go to war".