Seems like they're following Google's strategy. Presumably, ad profit from each individual user is low enough that it's cheaper to accept false positives in their anti-abuse mechanism than it is to provide a functioning appeal process. Maybe if the user manages to go viral on Twitter or HN with their story they could get it reversed. Going viral with stories of false-positive bans is the primary way to restore a Google account, it probably works for Reddit too. Normal people have to suck eggs.
At least losing a Reddit account is less life-disrupting for most people than losing their Google account.