Those are called smegma and they are bioorganic accummulation. These have unappetizing appearance and have poor odour; they also more importantly, contain bacteria and viruses and increase the risk of your female partners to get certain viruses. This fact can increase the risk for cervical cancer, and also infection in general. Many communities are circumcised; however, it is made popular along the religious line for whatever reason ie as if only Jewish and Americans and Muslims are circumcised. Inreality, many other world communities are circumcised for health and hygeine purposes