So given you don't believe there's any kind of scale to this do you think the publishing of child porn should be freely available and not censored?
There are both moral and legal issues that need to be discussed here. Ignoring all the other facets involved in the manifesto pledge and just discussing porn...
Child porn is both illegal and considered immoral for the majority of the population, the partaking in sex or sexual activity with children is also illegal.
The vast majority of porn is neither immoral or illegal to perform. Some just becomes illegal when being recorded and viewed by others. That's the issue being discussed here.
This government have already outlawed pornography involving legal acts between two (or more) consenting adults. Their manifesto pledge appears to be continuing down that train of thought and heading towards what appears to be an eventual goal of only allowing adults to view porn that is considered by the government as "morally acceptable", if any at all.
The legality of the acts recorded appear not to be being considered - although I would hazard a guess that May may well like to make many of those acts illegal as well - rather the moral viewpoint of a few conservative Conservative party members is the only thing that seems to matter.
Therein lies the issue. It's about control, porn just being the tip of the iceberg that is going to have less people defending it. Just as the continued use of buzzwords like terrorism, paedophiles and criminals is banded around way too often. The real issue is the laws and regulation could/will also be used to suppress dissent in other areas - the media for one.