The enjoyment of, is the clearest sign of a repugnant character.
Personally I think torturing animals for amusement is quite a big clearer in terms of measuring that.
Is it all that different, though? Isn't humiliation the central dimension of pornography? Isn't what excites in it exactly the thought of the total humiliation of the 'performers', their very sexuality now pulled into the domain of commerciality? 'Imagine being reduced to that!'.Humiliation is a central part of some pornography, but I don't think that's what gets most people who watch porn off. And I especially doubt that most viewers have even thought about the commercial aspect of it.
Most porn involves people who are enjoying the act, both male and female, so they aren't really experiencing humiliation. I think it's actually more likely the opposite of what you're thinking - the sheer shamelessness of it is probably more appealing to most people.