I wonder if that's a result of the rising pressure on researchers to get things out ASAP. As the Ricky Bobby saying goes, "If you ain't first, you're last." It's equally as ridiculous in real life as it was in the movie. But it reflects the growing sense among many researchers that their number one goal has to be to get a research grant, and one of the best things one can do for oneself to that end is to get a paper in Nature, Science, Cell, etc. When a reviewer looks at your grant, if (s)he doesn't know your name already (especially likely for young researchers, or, the people who need grants the most but have the hardest time getting them), they're going straight to your publication list. Seeing a paper published in one of the big dogs is a way to impress, even if good research can be published anywhere, as can shitty research. Sometimes whether a paper gets published in a high or low impact journal can have mainly to do with who reviews it. The system is very arbitrary, but it's nice to see people seeing flaws and retracting on their own, instead of these being cases of fraud, which would be far more troubling.