For you 1st point: because in most jurisdiction CP is absolutely forbidden and typically you are not protected if you don't proactively act to eradicate CP on your service with reasonable dilligence, whereas an upload of a film might or might not be problematic, given that it can be for private use or public distribution.
For the third point who are you kidding. Technically this is problematic. In the real world even representatives and people in grand jury exchange ripped films, most probably most judges do it too. So this is both technically a reason but an highly hypocritical one.