More to the point, the satire is obvious because the posts are absurd, over-the-top, and deeply implausible. Spray-painting your baby's mouth and crushing hormone pills to put in your teenager's food, then bragging about it on reddit, are not things people do. Writing a meandering post in southern vernacular about bounty hunting your sex partner is not a thing people do. Do people do insane things sometimes? Yes. But when you want to use a genuinely insane thing as evidence for any sort of political message, you should put more work into it than just assuming whatever outlandish story someone's spinning online that happens to be perfect culture war fuel is truth.
A minimal level of fact-checking and scrutiny would have been enough in this case.
If the "joke" is supposed to be similar to what Sacha Baron Cohen does, this isn't enough. Like his Erran Moorad stuff, a reasonable person would look up his claims before sitting in for an interview or "training" with him and asking for 3 year olds to be given guns. In Borat 2, the disguises seemed to be intentionally bad.
Most importantly, at the end of the joke he came out to the world and said it WAS a joke and publicized that it was a joke. What r/Drama is doing is less like a joke and more just ways to basically start a civil war. If they were genuine clowns and cultural critics like Cohen(who is literally a classical clown according to Wisecrack) they would come out and proudly declare it in public.
Their inability to verify the claims. The proper approach to journalism is to neither dismiss nor accept claims, but to investigate them. If the investigation yields a story, you publish the evidence collected; if it's a dead end then nothing gets published. In this case, the journalists clearly never did any actual investigation.