I guess you don't live in the same country as me where it _always_ rains.
Also plenty of people have have water damaged phones, from using them in bath, dropping then in the toilet or simply forgot to take them out of their pockets before plunging into the ocean. That you don't know these people or don't do it yourself, doesn't mean there are few water damaged phones.
Also please read: http://www.idc.com/getdoc.jsp?containerId=prEMEA42146116