I approach copying & pasting without a source from the angle of plagiarism not "fair use" or copyright. 99.9% of the time those copy & pasting full text aren't using sources that are public domain so it isn't an issue. Those that do post public domain usually do it in such a way that lets the reader know it isn't their work and/or they aren't spamming for upvotes or money.

The problem with those that are curating portions of articles and not adding any commentary is that it become prolific when one of them gets a nice payout. Everyone wants to jump on the $100 money train and some users start cranking out 20 to 30 copy/paste articles a day that only have a picture, a paragraph, and a link all copied and pasted. It becomes a spam issue. They even start copying each other and you see the same posts plus or minus formatting. They make finding unique and relevant content impossible.

Before phone verification it was pretty easy for users to get multiple accounts to do this. They can still buy accounts if they find it profitable. And it is. They are using @randowhale, @esteem, and other initiatives here to get up-votes.

There are a lot of days I would like to throw in the towel when in just a few hours I find 10 or more accounts that are less than a day old just copying and pasting anything they can find they think might get someone's attention and a vote. The more ambitious ones have added comment spamming trying to drive traffic to their posts. Luckily most haven't figured out how to game the system and give up after a couple of days.

When I first joined steemit there were a couple accounts that were so high in rep and sp that they could copy, paste, & up-vote themselves to turn a nice profit without ever actually interacting and being part of the community.

Sorry my comment turned into a mini rant...