Of course, I'm not trying to suggest that a third-party prophylactic tool is a definitive solution to what is ultimately a separate problem, just trying to be pragmatic here and restore basic readability for end-users, whether the filtering is done at the source or after the fact.
Let's be real here, we are talking about unmoderated magazines on an instance where the developer is AWOL and using a framework that is lacking many basic features. Even with moderators, manual moderation can be a big ask and is time-consuming for free volunteers, depending on the volume of posts or how rudimentary the moderation tools are.
I actually don't read kbin magazines much, so I wasn't aware of the extent of the problem until I started opening those magazines more closely, and felt that something is better than nothing.
On the magazines you mentioned, I do see a few anomalous patterns that I'll start filtering. For the most part, with filtering enabled, they were almost entirely free of garbage, save for a few patterns I may have missed on the first few passes. /programming and /food I need to take a deeper look at. The /food thing is good intel, because the use of Amazon referral links in the threads is something that can be generalized to other situations beyond books. Posting referral links is definitively block-worthy.
I also noticed some stuff that by any other name would be considered a thinly-veiled ad, such as specific users only posting articles to web sites they own and operate. I'm not talking about bots as such, but actively promoting one's own content--even when such content is on-topic for the magazine. I declined to filter this stuff yet, because it received a lot of upvotes and seemed to be received favorably, maybe because the readers felt it was at least germane to the topic at hand? I think this is probably true for /food as well, because the line between "content" and "promotion" is unclear here, since what is a food blog if not a product generating click revenue? It seems like the tolerance threshold for that sort of thing is higher in a magazine like /food versus some other magazine. Anyway, I digress. I'm not treating such stuff as in scope, just filtering what is blatantly noise.