In other words, the evidence isn't all that good.
No. Saying that costs and side effects aren't worth something is very different than saying it doesn't work and produces no effect.
Conventional treatment is often cheaper than chiropractics. Dismissing it on those grounds is very different than dismissing it on grounds that it produces no effect. Given that they don't like it they need to make some argument against it ;) Not being able to argue that it doesn't work make them go for risks and cost effectiveness.
This is a no true Scotsman fallacy. You're asserting that anyone who seems to be part of conventional wisdom but doesn't agree doesn't count because he doesn't care about evidence.
Cochrane meta studies have a reputation that's good enough that even venues like RationalWiki accept it when it comes to conclusions that they don't like.
There no meta study that's published after the Cochrane results that argues that the Cochrane analysis get's things wrong. Conventional of evidence-based medicine than suggests to use the Cochrane results as best source of evidence. It not only RationalWiki. Any good evidence-based source that has a writeup about chiropractics will these days tell you that the evidence suggests that it works for back pain for a value of works that means it works as well as other conventional treatments for back pain.
Saying that costs and side effects aren't worth something is very different than saying it doesn't work and produces no effect.
No, they're not very different at all. In fact they are directly related. Saying that costs and side effects are too great means that costs and side effects are too great for the benefit you get. If there is some probability that the study is bad and there is no benefit, that gets factored into this comparison; the greater the probability that the study is bad, the more the costs and side effects tip the balance against getti...
I just finished the first draft of my essay, "Are Sunk Costs Fallacies?"; there is still material I need to go through, but the bulk of the material is now there. The formatting is too gnarly to post here, so I ask everyone's forgiveness in clicking through.
To summarize:
(If any of that seems unlikely or absurd to you, click through. I've worked very hard to provide multiple citations where possible, and fulltext for practically everything.)
I started this a while ago; but Luke/SIAI paid for much of the work, and that motivation plus academic library access made this essay more comprehensive than it would have been and finished months in advance.