Why in the song "Vertigo" does Bono speak spanish?

I don't get it. He goes from spanish to gaelic. Anyone know why? And does anyone else here think he's getting a little too preachy? I admire his work and everything, and I think what he does is awesome, but when I pay $75 for a ticket I want to see a good show, not hear about all the stuff I can read about in the paper.