It absolutely is relevant. Its not really about how hurtful these words are (although like any slur it can be very hurtful), its about how much we use them without thinking. Its how we have allowed these words to become a 'normal' part of social interaction. When calling someone you don't like a ****** or something you think is stupid gay becomes a normal thing, it can cause subconscious disdain for the group associated with those words. For example, lets say little Johnny has no idea that in the humble small town of Placeville people hate gays and they are outcasts. His friends always call people they don't like ******* and things they think are stupid gay. Eventually, just to fit in, Johnny starts saying gay and ****** as well. Over time he develops an association with 'gay' being a negative thing. When the class discovers that the new transfer student Jerry is actually gay, Johnny naturally feels that is a negative trait due to the words that he has used for so long building up an association.

I think its pretty obvious that on the internet people are ****ty to each other due to not having any real consequences. I don't think pointing out sociological trends using sites like this is anything near lazy. Sure, slurs have popped up against groups of people since the dawn of language, that doesn't mean we shouldn't try to shed light on them as a bad thing and try to fight the bigotry against those groups in society that is almost always associated with these slurs.