It's clear enough to me. In a well written article, he's advocating a middle way.
On the one hand, if you borrow an idea from another person or source, then you should cite it. Just because it's only the arXiv doesn't give you a pass not to.
On the other hand, "flag-planting" articles are not something that you borrow from so you don't have to cite them - and you shouldn't as the practice should not be rewarded.
As `CogitoCogito points out, it's routine to cite completely unpublished material such as private communications.
Conversely, if a flag-planting article somehow makes it into a very prestigious journal, then you can still ignore it.
So really, the publishing status is only an initial filter, and the potential source should always be judged on its merits.
But this implies that you could re-implement/modify/publish something from a paper and just not cite it because you deem it to be nonsense. That's surely dishonest. If you've read something which closely relates to your work then it's your responsibility to make this clear, whether you like the paper or not.
If it doesn't relate to your work, or you haven't read it, then obviously it needn't be cited.
I did, I don't get it though. I think it's dishonest to read something and decide yourself that it's not worth mentioning, even if your work relates to it in some manner.
To take an example, read the article linked to in the OP's. The author describes how terrible two papers are (implying that they're not worth citing) only for one paper's author, and other researchers, to come on and tell him why he's wrong about his interpretation and understanding. This leads to him retracting his claim that it wasn't worthy of merit.
So immediately you have an example of a sole researcher deeming himself to be the only judge of merit necessary, only to be wrong. His judgment has a 50% failure rate already, and that's with him cherry-picking 'bad' papers.
> So immediately you have an example of a sole researcher deeming himself to be the only judge of merit necessary, only to be wrong.
If you have chosen to publish on arXiv, then you have chosen to step out of the peer-review route. The author of the linked article did not deem himself to be the only judge of merit necessary, his position as sole reviewer came about through the decision of the papers' authors to publish on arXiv, and it seems the article's author would have preferred it if the papers had been well-reviewed before publication. You are not advocating for arXiv papers to be immunized from evaluation, are you?
It seems that we are rediscovering why the peer-review process, with all its flaws, was created in the first place. Complex problems rarely have simple solutions.
On the one hand, if you borrow an idea from another person or source, then you should cite it. Just because it's only the arXiv doesn't give you a pass not to.
On the other hand, "flag-planting" articles are not something that you borrow from so you don't have to cite them - and you shouldn't as the practice should not be rewarded.
As `CogitoCogito points out, it's routine to cite completely unpublished material such as private communications.
Conversely, if a flag-planting article somehow makes it into a very prestigious journal, then you can still ignore it.
So really, the publishing status is only an initial filter, and the potential source should always be judged on its merits.