Is/was copy/pasting from Stackoverflow considered harmful? You have a problem, you do a web search and you find someone who asked the same question on SO, and there's often a solution.
You might be specifically talking about people who copy/paste without understanding, but I think it's still OK-ish to do that, since you can't make an entire [whatever you're coding up] by copy/pasting snippets from SO like you're cutting words out of a magazine for a ransom note. There's still thought involved, so it's more like training wheels that you eventually outgrow as you get more understanding.
You might be specifically talking about people who copy/paste without understanding, but I think it's still OK-ish to do that, since you can't make an entire [whatever you're coding up] by copy/pasting snippets from SO like you're cutting words out of a magazine for a ransom note. There's still thought involved, so it's more like training wheels that you eventually outgrow as you get more understanding.