I think OP is saying that it can become less straight-forward to apply judgement in some real-world situations (which is encapsulated in the old adage "the map is not the territory", which I guess I thought _was_ common language but we all love in our own bubbles, I suppose). Anyway, I believe the reason that is often cited for why child pornography is so bad is because it involves the coercion/exploitation of a human being that is unable to consent. I believe OPs position is that if this harm is removed, there would need to be some other grounds on which to prosecute someone. That is, some identifiable harm would need to be demonstrated.

There may be a reasonable counter to this argument but I would not say that OPs position is "bogus" on is face.