I'm guessing they lost their back issues due to neglect and sometimes tragedy. When people are first starting out they often don't think that in 30 years time they will want a physical copy of their joke periodical and warehouse space is always limited. When budgets get tight it is sometimes the storage bill that has to be cut.

They had a mood swing ahead of the 2008 election, and truly hilarious characters like Herbert Kornfeld were canceled.

https://theonion.com/cash-room-bitch-be-havin-my-shortie-181...