For those who like to offend it's a power thing, they have the ability so they are proud to use it. I notice this habit forms most quickly and primitively in teen groups among the lower ranks, their conversation centers around making fun of others, scaffle holding every other word with f this and f'n that. A pretty pathetic case.
Another instance where back talking became the "in" thing is in my college english class, where the students talked with energy and animation on the topic about how weird the senile the teacher is. It's like they are afraid they can not connect on any other level other than ganging up on somebody. This is probably more normal than my last example because the previous group was composed of under-aged drinkers and pot-heads.
I do appreciate it when the offender is taking advantage of people who are overly sensitive or have something to be ashamed of.
I guess it's not important to me because I remain detached. Sometimes I'll blurt out something that makes even the offensive extrovert type, who you can visibly see they "work" to be less offensive because it comes naturally to their perceptive extroverted personality, recoil. They would say something like "Flanny, you always make sure you're around because of those great and rare comments." I don't have a sense where the boundaries are like they do, so I might say something much more offensive than I meant to.