Why we haven't communicated with any other civilization yet? If the civilization would exist right now in some other galaxy, it would take millions of years for the signal to arrive - have you considered that. And what makes you so sure; we haven't received any signal from other civilizations? Maybe we are just stupid enough not to recognize such signals, as we think that every life form out there must fit in our earthly standards. Maybe if we would start to think more open-mind we could find more unbelievable miracles of our universe out there. I wouldn't be surprised, if some kind of life would exist also in our own Solar system – for Example on Titan, and I would be even less surprised if we wouldn't recognize those life forms at first.