> I´d say those who feel the need for a device like this are guilty by association of farting and burping even louder than average, why otherwise get something to mask their clearly obnoxious and dare I say noxious emanations in the privy?

This seems like a jump. Social etiquette is important. A desire for visitors (or others) not to be subjected to the various sounds emanating from the bathroom is a form of politeness, not cover-up of something more sinister.