Morality, in my humble opinion, is a subjective thing, but that doesn't mean I am good because I say I am good, or that is bad because I say it is bad. See, we can have different ideas of what makes right and wrong, but the things we form our morality on aren't so nebulous.
Suffering is a thing. Happiness is a thing. Culture is a thing. Living as a person in a system that requires masses of people to coexist in order for society to function. That is definitely a thing. All of these things are what we base our morality on.
So yeah, morality is a subjective thing, but so is humor. You can make a crappy joke just like you can make crappy morality.