Same here. I love mixed genres. But chocolate is still chocolate and peanut butter is still peanut butter. Words should have meanings that actually mean something, otherwise we might as well just say "stuff" and "thing" all the time.
But what words mean should be a factor of how they're used. If the majority of the population has used a word in a certain way for a generation or more, it doesn't make sense to cling to some old, hyperliteral, prescriptivist definition for it, because most people don't use it that way. Words aren't antiques to be kept up on a shelf gathering dust, they're living entities, everyday tools for communication. So the "correct" use of a word is the one that is most clearly understood by the most people, even if that usage has changed from its origins or literal definition. Countless words we use today have changed in meaning from how they were originally used, and trying to cling to their original definitions would obscure communication, not promote it.
Of course one shouldn't use nonstandard definitions recklessly, since communication requires clarity. But if a "misuse" has gone on long enough and become widely enough accepted to be the default standard usage, then resisting that change works against clarity, not for it.