You heard about how Voyager "ruined" the Borg? It's because of the 8472 and "Scorpion" alone. They just couldn't handle the simple IDEA of there being another force out there that could fight them on equal terms. And that Voyager was the series to introduce them was an unforgivable sin.
So you want a source, look at how Borg fans view Voyager.
While I've heard about VOY ruining the Borg, I've never heard that explicitly tied to 8472, but rather overusing them in general. I'll repeat my request for an actual source.