These are different concepts. The adding of new words or uses, as in your example, is one thing.
Making incorrect, but widespread, usage "acceptable" by including it in the dictionary does happen, but it's a different event. And, yes, it can make things "legitimate." But it just epitomizes and exacerbates the dumbification of America. in the written (and spoken) language.
But your gonna stand by this...and there are a lot of people who could care less
Cheers.
Dumbification of America.... your vs you're ... as an example!