The benefits of smoke detectors very clearly outweighs the costs of smoke detectors in every household, by a very large margin. Further, smoke detectors are not intrusive. Unless there is a fire (or the battery is running low), most people will not even notice the presence of a smoke detector.
They run on RADIATION! Radiation causes cancer! I don't want a cancer box in my house or near my children, thank you very much. Take your Big Phire shilling somewhere else.