In my opinion, if you used Wikipedia, you should cite it. If you instead got your idea from "lunch room conversation", or a private email, or whatever, you can also cite that. It's a really huge problem that people pull ideas from Wikipedia, attribute them to something like "paper 4", but then it turns out that what Wikipedia said and what papers 3 and 4 said were not the same, and what Wikipedia said was actually based on some other paper 5 that turns out to be a bunch of bullshit, or a Wikipedia author made it up and wrongly attributed it to paper 3, or a Wikipedia author didn't understand paper 3 and made a total hash of it. Etc.
This of course also happens plenty when Wikipedia isn't involved, but for whatever reason people seem to have the mistaken idea that citing Wikipedia is inherently bad. There's no rule against citing Wikipedia, or tertiary sources in general, from professional work.
When a later person (e.g. a scholar or Wikipedia author) is trying to understand your work, it's incredibly helpful to know where some claim or idea came from. Otherwise they have to jump through extra hoops to trace the actual attributions and figure out where mistakes came from.
Wikipedia's original research policy is not relevant to what works you should cite in academic papers. A Wikipedia article is not supposed to contain the original research of its authors, because it's the wrong venue for such work, and because when such material is added it typically turns out to be nonsense or spam, but rejecting it on the grounds that it is unsourced is much easier.
> In my opinion, if you used Wikipedia, you should cite it [...] It's a really huge problem that people pull ideas from Wikipedia, attribute them to something like "paper 4"..
Your solution for using unreliable Wikipedia is to cite it. My solution (and the way I was taught) is to simply _never use it_ for stuff which goes into the paper.
If I wanted to claim something ("widgets are quux"), I might certainly _start_ with Wikipedia, just to make sure that my understanding is correct and that I am not wasting my time, but if I want to use this in the paper, I will need to move to primary sources, read them and ensure that there is a good evidence that widgets are indeed quux.
So now that I spent all that time reading primary sources, I'd certainly cite them and not Wikipedia - after all, primary sources are better, and a single citation is enough. And in the case the Wikipedia author was wrong, I will avoid a mistake.
By extension, if I am citing Wikipedia, this means I have not found/read any better sources, and that just shows that I am lazy or maybe those widgets are not quux at all. Any advisor/reviewer would immediately point to this mistake - "Why are you citing Wikipedia here? Find a better source or remove the claim"
And that's how the rule is made - it's not "Don't cite Wikipedia [put ideas unattributed instead]", it is actually "Don't cite Wikipedia [find a better source and cit it instead]".
(Although I agree that some lazy people do former rather than latter)
If you never do research on Wikipedia, then fine, don't cite it. That's kind of irrelevant though.
> after all, primary sources are better
This is sometimes true, and sometimes not. For some topics, the Wikipedia article is an amazing overview, significantly better than available alternate sources.
> in the case the Wikipedia author was wrong, I will avoid a mistake
Wikipedia authors are not the only people who can be wrong. All kinds of sources, including primary sources and scholarly secondary sources, contain factual errors, sometimes subtle ones. You should certainly try not to say wrong things, which is why you should approach all sources with a critical eye.
But people cite non-primary sources all the time. The most important thing is to say where you got your ideas/claims, because when you don't, the result is misleading to your readers. If you get your claim from one source, but then cite a different source, that's terrible practice that causes significant trouble. But this happens all the time, and telling people to "never cite Wikipedia" is a major contributor.
This of course also happens plenty when Wikipedia isn't involved, but for whatever reason people seem to have the mistaken idea that citing Wikipedia is inherently bad. There's no rule against citing Wikipedia, or tertiary sources in general, from professional work.
When a later person (e.g. a scholar or Wikipedia author) is trying to understand your work, it's incredibly helpful to know where some claim or idea came from. Otherwise they have to jump through extra hoops to trace the actual attributions and figure out where mistakes came from.
Wikipedia's original research policy is not relevant to what works you should cite in academic papers. A Wikipedia article is not supposed to contain the original research of its authors, because it's the wrong venue for such work, and because when such material is added it typically turns out to be nonsense or spam, but rejecting it on the grounds that it is unsourced is much easier.