If the person re-whatever do their due diligence and post source along with the art in question, and people can't be bothered to look into it when it's right there, that's not the person re-whatever-ings fault.
I'd far prefer if everyone had direct links to source over reuploading in every case, but by nature of the internet that can sometimes be either impractical or straight up impossible. In fact, whenever I go looking for art, it's extremely rare that I ever not see source, either tangentially or more commonly by the re-whatever having source there.
My points have been directed at the mindset that no one should use "my stuff" ever, not people intentionally spreading things with proper credit in tow.
There's a reason that asking for source is such a ingrained meme on every board of 4chan.