Subreddits could often be narrowly focused to a severe degree.

r/whatisthisthing would routinely remove comment chains that were tangent to the topic of identifying the thing posted. Say someone posted a picture of a Betamax tape and said "What is this thing?" Someone identifies it as a Betamax tape, links to the WIkipedia page, mentions that it was Sony's competitor to VHS, etc. Que a tangent where someone says "VHS won the format war and became basically the only standard available, so for a long time we didn't call the format by its name; commercials for movies would say "now available to own on video" and we called the machine a "VCR." And someone else says 'There was actually an early and unsuccessful format called VCR, it didn't do well and is pretty rare though." And all these comments get removed and the commenters get 7 day bans.

I've yet to see that brand of "the kind of anal retentive you only get from welding someone's ass crack shut from spine to scrotal seam" here.