First, when we speak about a sexual orientation, we need to understand that whatever you attribute to a sexual orientation such as homosexuality may also apply to other sexual orientation such as pedophilia.
As for your argument that pedophilia is not a sexual orientation, professionals in this area disagree. Here is a quote from the National Register of Sex Offenders website:
"Pedophilia involves sexual attraction/orientation towards children, and usually involves males." (Source:
What is Pedophilia and why is it such an epidemic? - RegisteredOffendersList.Org).
There are other sexual orientations also.