Yes it is as commun as the flu and both are illnesses. What is your point exactly?
"Homosexuality is assuredly no advantage, but it is nothing to be ashamed of, no vice, no degradation, it cannot be classified as an illness.” Sigmund Freud 1935
Anyone that masturbates would at the very least have to concede to being a pervert themselves first if reproduction is the only non-perverted sexual act:P (I may be a pervert, maybe).