[williamstein]

I'm a professor (in mathematics), and there are some reasons why I personally might say "yes" to review a paper. (1) If the paper is so interesting that when I see it I think "I really, really want to read this paper!", then I am likely to peer review it because as a reviewer when I read it, I get to ask any question and the author will take my questions and concerns very seriously. (2) I owe the editor who is asking me to peer review the paper (or maybe even the author of the paper), e.g., if the editor put a lot of work into ensuring a paper I once wrote got properly reviewed. (3) Even if I say "no" to fully reviewing a paper, as an expert in the area I can often provide quick valuable feedback about the relative value of the claimed contribution, and who is most likely to be suited to review it; I'll do a quick informal review like that in some cases.

From the outside, it is easy to forgot the extreme extent to which academics are motivated by (or view themselves as motivated by) principles of "good citizenship". This is selection -- the people who aren't this way, often do not get hired or promoted. Also, many academics (at least in pure math) view motivation for money as a "lower order term". It's a good thing for them, because for much of your long career in academia there is little you can do to impact your salary, besides applying for a job somewhere else. For me it's always been: each year you get some maximum possible merit raise of between 0% and 4%, depending on external economics that the department has no control over. Academic book royalties might also raise your yearly salary by 2%. Being highly money-motivated in some parts of academia would end up being very frustrating indeed. E.g., even when I've got a big NFS grant, that doesn't change my salary one bit; instead, it changes how many students and/or postdocs I could support.

[apathy]

Well, yeah, but without students & postdocs it is very difficult to make a material impact on your field of endeavor.

There’s also an ulterior motive for some lines of work, where sending a paper to be critically reviewed by rivals is a mechanism to torture test the work & conclusions.

This can be taken too far (especially in biology, the glam fluffing and $million additional irrelevant experiments are legendary), but in principle, if even your most motivated critics can’t find a fatal flaw in your work, it’s a reasonable bet that the work is sound. At least, that’s the principle. Editorial overrides sometimes break this safeguard, though (lord knows I’ve seen a few).

[ylmm]

Well, yeah, but if you submit a paper to "torture test" and it gets rejected, that cuts off a journal to be able to submit to.

Well, yeah, but I think what he's saying is it's probably the case that a large number if not majority of academic make the decision to go through the grueling PhD process and give up years of earnings in their prime for things other than monetary gain. But of course people can become disillusioned later down the road.

[apathy]

I claim that it’s better to request major revisions than recommend rejection, but that’s mostly due to my lack of faith in authors.

Too many examples of “oh well, let’s try the next journal” and not enough of “gee maybe we should fix these glaring flaws”. It’s not because I’m a nice person; it’s because I would prefer the literature not to be a toxic waste dump. Nobody is entitled to be published anywhere. In an ideal world, doubly blinded review would become a part of the published record. At some journals it already does.

The reviews offer valuable context, which is often sorely lacking in high profile venues. (The canonical examples of STAP and arseniclife come to mind, but also much more subtle details where an overall sound paper somehow only gets cited for the one shaky assertion in the results)

JMHO