I've always thought of Mexico as a noisy country. Service trucks drive through streets blaring messages and riffs over loudspeakers. Bars ahd shops blare music through open doors that can be heard blocks away. Horns are honking, roosters are crowing, and dogs are barking. Nobody sends to get bothered by somebody else's noise. Of course, there is a time and place for everything, including quiet.
I think of most restaurants as a place for boisterous conversation. Someone mentioned a quiet zone sign so maybe El Moro is aiming for an upscale fine dining atmosphere where whispered voices join the tinker of silverware over soft piano music. Still, large groups tend to be loud groups so maybe restaurants that want quiet shouldn't seat tables of 12?