I used to use these terms myself. In my last year of high school, I began to eliminate my uses of them.
As somebody who's bisexual (which includes being attracted to men just as equally as a gay man [or the same idea for a gay woman]), I don't particularly take offense to "gay" but when I hear it thrown around for every uncanny instance, I have to sit back and be like, "really?"
There is such a thing as context and I am aware that most people mean these things harmlessly. Nonetheless, while nobody can really force censorship rules on anyone, nor should any such restrictions be enforced, it simply would be a gesture of sympathy for other human beings that would more than likely lead to things like being a more respected player and possibly earning more friendships. More importantly, as others have pointed out, it's about the community's image as well.
Soooo, to be brief: it's not necessary to curtail the abuse of the words "gay" and "****", but cutting these words from one's Smash vernacular would be doing oneself and others a favor. I'm not expecting anybody to go through with it, but I will respect others who, at the very least, care.