We all know that publishers add little value to science, and nature here looks to be striving to add even less than usual. If the peer reviews are not of good enough quality, your editors should be handling that! Don’t rely on the readers to review the peer review. Dumping the peer reviews online is just a way to avoid the responsibility of quality control.
Conversely, it's also a way for the general public to see criticisms and laudations of research that might otherwise be accepted with blind faith. While Nature has its pick of comparatively incontrovertible research, sending a signal to the rest of the industry that peer reviews ought to be published seems like a useful step toward better, more replicable, more honest science.
> While Nature has its pick of comparatively incontrovertible research
Nature doesn't actually attempt to select for incontrovertible research, but rather the most groundbreaking/noteworthy research. Which is also why their retraction rate (and those of other "top" journals) is higher than average.
(Disclosure: I'm part of an initiative that explicitly distinguishes between exciting and robust research for this reason.)
