I don't use Ancestry to make a tree, but I do have one on Rootsweb WorldConnect which I update every couple of months by uploading a GEDCOM. You are correct, though, that there are people who don't want to do any research, but only want to just copy someone else's tree entirely, without even doing a bit of checking on what is in it. I don't mind that people use the info I put out there to help them find their families, that's what it is there for. But the point in the tree is to use it as a guide and for them to verify that they are indeed connected to the people in it, and exactly how they are related. I've found so many trees on Ancestry that are total embarrassments because much of the info doesn't make a bit of sense. Parents having children 100 years after they are dead, people getting married 10 years before they are born, spouses having children with different people in other States that they never set foot in, it is clear those trees are not being researched nor are they even being looked at by the owners because anyone with common sense would see how ridiculous some of the info is. There are many threads on the Ancestry Comments Boards discussing the bad data that is going into those trees which people can do themselves some favors by reading them before copying someone else's data. Just the other day, someone just getting started posted a message complaining that they were having problems downloading dozens of trees from Ancestry to merge them onto theirs, all of this without doing any research. This sounds like someone doing the exact thing you're talking about Cynthia, it is apparently what some of the newbies are doing, perhaps not understanding, or maybe not caring, that it is not the way to do family research.
Some people really need to learn how to not just accept anything that comes up in Ancestry hints, and if they do accept something, to make sure it is correct, and to not let the info override what is already correct in their trees. Trying to encourage people to use good research habits, is something that we are all trying to promote.