Why does everyone believe nearly everything they read on Reddit?
Unlike, say, 4chan, which welcomes its prospective user with "The stories and information posted here are artistic works of fiction and falsehood. Only a fool would take anything posted here as fact.", letting you know that whatever you read should not be taken seriously, Reddit built its fame on the premise of hosting actual stories, discussions and mostly "real" people (officially planned/announced/endorsed celebrity AMAs, user verification by mods on certain occasions). This problem is enhanced by the way it currently works: it is an echo chamber, based on a system that rewards posting formulaic bullshit for long term gains (upvotes/karma), and houses so many people who behave like living satires of the current US left that determining what might be real and what might not is, at times, like punching fog.
Some stories, like the Legal Advice one you pointed out, are easily rooted out. So are many others, like one we saw recently on the Tranny Sideshows thread, about a 20-something guy living in a highly controlling family of ultra-conservatives who tracked his every move... but didn't notice him gulping down HRT, losing several inches of height somehow, growing C-cup tits and an hourglass figure, and undergoing facial reconstruction surgery.
But, sometimes, you just can't tell. Someone posts about COMPLETELY OWNING their religious sheeple dad for asking them to stop acting like a complete degenerate for ten minutes: is it Euphoric Fedora'd Coomer #55872 posting his usual delusions, or someone merely gaming the system for awards?
It's the 37th post of the day on AITA about a transphobic bridezilla who won't let poor old Uncle Bob show up to her wedding in a microdress and stilettos. Do you think they will get all the updoots, or all the updoots and a Fort Knox's worth of reddit gold?
Things have become so ridiculous that, sometimes, it just isn't worth the effort of finding out if it's a lie.