Yes. I have tried this. Espionage points become Culture points. However, the number of Culture points needed to achieve each culture level go up far more than the number of increased culture points converted from espionage. So, if you don't care about culture levels and don't like the espionage system, go ahead and disable espionage. However, if you enjoy using the culture system, whether for culture victory or for city expansion and passive conversion of your neighbors' land and/or cities to yours, then putting up with the espionage system is a better idea. (Since I like the culture system, I put up with the espionage system, even though I dislike it.)