I always love how this guy thinks.
Respect is a big deal. It's hard to earn; harder to keep. There was a time when it was assumed that you automatically respected anyone who was older than you, or in a position of authority. Now respect seems to move laterally. You can like someone, but not respect them. You can also respect someone you don't like. I have more respect for some of the kids I teach than some of the adults I've worked with based on many different factors. And we don't respect everyone equally for equal reasons.
Very often, we fail to outwardly respect people in favour of our "right" to exercise our freedom of speech. I won't bore you with the details of how that freedom isn't available in Canada like it is in the US. I will enlighten you on the fact that people have feelings, and that if you decide to trample on them, don't be surprised when people get upset, even if you don't know those people. Even if you didn't intend for those people to hear. Especially if you say something that could, at any point in history, be considered offensive.
My example, I do not like being called a "broad" or a "chick". I am a woman. I find those terms derogatory. I will likely call you out if you use those words to refer to women. I don't care how many other women would giggle, think it's cute, or just roll their eyes at your ignorance. Those are words that subjugate me as a human, and I'm not just going to smile sweetly while you say something that offends me.
What Asher Roth said was much worse, but it's analogous in that it's something patently offensive. In this case, as proven by another douchebag. It's not about the offended people needing to "lighten up" or "have a sense of humour". It's that we are all entitled to respect and to define what makes us feel respected. If you say something that squashes someone else, take responsibility for it. You'll probably come out seeming less of an asshole in the long run.