Incredibly shaky research will get frontpaged because it resonates with popular political themes, and it receives the full clout of the name of science in the minds of reddit's userbase. For example this thread[0] which was peer reviewed in a journal that is openly written from a "feminist perspective"[1]. It may pass r/science's standards for being scientific but when a journal shares the same biases as the researchers they're reviewing that's a problem.
But if, say, Gerard t'Hooft were to write a great blog post about modern physics it's not welcome in r/science because it's not a peer reviewed paper, even though it probably has far more scientific merit than a lot of stories that r/science pushes to the default frontpage.
[0] - http://www.reddit.com/r/science/comments/22vbpp/barbie_expos... [1] - https://en.wikipedia.org/wiki/Sex_Roles_%28journal%29
This is a common occurrence in /r/science.It even becomes common(and popular) whenever some article comes with a "breakthrough" to ask "why isn't this true, like the rest of the noise we hear from the news"-and get very good answers.
And the discussion is very good, with scientistcs chiming in, explaining the details, the implications, and how is it related to other research(for example to other disease).
And AFAIK, it's one of the best places on the web to get critique and review and discussion scientific research- that is available to layman.
[0]http://www.reddit.com/r/science/comments/22vbpp/barbie_expos...
Take the Barbie story as an example. Even when it was becoming clear that the study was weak, that the reviewing journal shared the same biases as the researchers, that the title was misleading, etc. the mods didn't do what's common for other large subs which is flair the title as "potentially misleading" or "early study, may not be reproducible" or just something to let the casual viewer know that this isn't science in the way that what's going on at CERN is science.
It was a while ago, I think I called out some feminist bias in a thread (not the Barbie thread from above) and a few of my comments were deleted which I didn't think was called for. When I messaged the mods my concerns weren't addressed and I was stonewalled. When I was unhappy about being stonewalled I was threatened with the banhammer.
It's worth noting I've spent far more time in r/askscience and I have zero complaints there or in any of the other science/engineering subs.
On the plus side I have a better understanding for the complaints creationists and quantum mystics have about dealing with people who study science, which helps in dealing with friends and family.
[0] https://www.reddit.com/r/science/wiki/rules#wiki_submission_...