It'd be hard to tease out, but I suspect most of the taboo associated with liking "teens under 18" would be for adults interested in teens under 18; presumably

It'd be hard to tease out, but I suspect most of the taboo associated with liking "teens under 18" would be for adults interested in teens under 18; presumably not many would consider it taboo for a 16 year old to be interested in other 16 year olds (which would be some of that 30%).