The people who use insensitive words without realizing that their words could potentially be hurtful should get a pass, in my book. It is okay to excuse someone who doesn't know any better. The people who use these insensitive terms just to be insensitive and offensive aren't very nice or considerate; believe it or not people like that exist. When it comes to proving a point, some harsh words might need to be heard to illustrate more vividly what one is trying to express. It is up to the interpretation of the individual if harsh words are to be taken with a grain of salt or taken to heart. When someone says something mean and offensive to me, I try not to make a big deal of it. Sometimes its hard not to make a big deal of it.
Thing is words are just words, at the end of the day. So what if someone calls you a bad name or slanders you in a lewd fashion?
As long as people are free to express an opinion, you will always be free to disagree. You might not like it that people can say things you don't like to hear, but you need to appreciate that. Not appreciate people saying negative things, but appreciate the right of people to say negative things. If someone has offended you with words, you can always give them back some of your own words and let them know how their words make you feel! Sometimes you just have to let it go and be the bigger person.
As far as implied negative connotations associated with words such as gay, cancer, autistic, etc....
Nobody should be getting outraged by what any self-absorbed teenager has to say; if a person is well into adulthood and still saying immature things like this, there may be no hope for that person and therefor nothing you could do would probably have a positive result. Teenagers are attention-whores and will say stuff like this just because it might get a rise out of some folks, as long as this type of trolling is acknowledged then I can't see it going anywhere in the near future.