A plot of the journal retraction index versus the impact factor revealed a surprisingly robust correlation between the journal retraction index and its impact factor (P < 0.0001 by Spearman rank correlation) (Fig. 1). Although correlation does not imply causality, this preliminary investigation suggests that the probability that an article published in a higher-impact journal will be retracted is higher than that for an article published in a lower-impact journal.
The charitable interpretation is that high-impact journals are willing to take higher risks in exchange for a bigger splash. And of course there is a not-so-charitable interpretation… a focus on big splash and getting a big scoop trumps scientific rigor.