I think, in a time before porn, masturbation probably wasn't bad, or wasn't necessarily bad. Of course, I could see a person getting carried away with masturbation without porn, someone that would just be too indulgent can live for pleasure. But now that porn is in the picture, masturbation is different I think. It's not just a natural thing anymore. It's tricking our brains into thinking we are actually having sex. It hijacks the brain and brings something very unnatural into people's lives.
Porn is unnatural, masturbation is natural, the combination of both is unnatural. It's a tricky question I guess.