Yes, but you would never take a painting done by Da Vinci originally, if you were by some small chance able to come up with an original painting, slap some modern pant over the top of it in the same exact pattern and then call the painting wholly yours, would you?

A plagiarist is stealing another persons words, regurgitating it, and saying "it all, wholly, came outta my ass." That's not cool. Not cool at all.

There's a difference between copying art - in school we were taught to copy and emulate famous paintings in the hopes that we could grow our artistic abilities, just as in writing classes I have, we are taught to write in the style of famous authors. That's learning, stretching the creative juices and that IS culture.