Yeah, no one was saying that. I think you've got a bit of a chip on your shoulder and tend to take things in the most extreme way, which is cool (and might serve you well as a writer), but takes conversations a bit too far. Hell, I was trying to be encouraging! I do think a truly unique and different story is absolutely the best a writer can aspire to. But those good, unique ideas are very few and far between. Not because writers are lazy, but because there has been a HELL of a lot of writing done. Same with music. But, the other side of the coin is that just because something has been done before doesn't mean you shouldn't do it. And, to mix metaphors a bit, standing on the shoulders of giants will get you further than reinventing the wheel.
My point was simply this: be unique if you can, but that shouldn't be your primary concern. Being GOOD should be. Eventually, hopefully, you can get to both.
But your West Side Story example is a good one. You know who made a career out of recontextualizing old stories for a modern audience? Shakespeare. Arguably the best and most influential writer of all time, and NONE of his ideas were new and unique. Food for thought!