So Dan Harmon, co-creator of Rick and Morty, explains Rick and Morty's Season Three hiccups:
... Justin [Roiland] and I are very regretful about the season taking way too long. I want to explain "what happened" because it's way less dramatic than you might ever imagine. Post internet TV audiences are so used to finding out there's an intriguing/confusing/intense reason 4 delays. And Christ knows if you've ever seen MY name on the internet I've only got myself to blame for an association with intrigue/confusion/drama.
But the truth in this case is so very boring. I will put it to you as objectively as I can, though we aren't talking about an auto plant. The reason S3 took long is because it took long to write, because it was S3 of a show that we were scared to make worse than S2 or S1. It's a common yet odd phenomenon. Tail-chasing, perfectionism, overthinking? One prob is that any description you pick for it is going to have a falseness. If I say "we overthought" someone else could say "well, no, we thought the right amount," it's like talking About religion or something. It feels I think, to writers, sacreligious and ineffective to open the creative process and poke and label.
But don't worry about the content, because, the reason overthought slows you down is, you just do way more versions of stuff than needed. You usually end up back where you started. So as far as I can tell, although I'm too close to it, it's just another good season of RAM. That took way too fucking long to write because it just seems like the same stuff that took way less time to write. That's it. Boring answer.
As I speak, more articles are coming out about me and Justin fighting. Because it's a less boring reason for a season to take long, and because I'm Dan Harmon, so it's a smart fucking first guess, it just happens to be hilariously not true even in the slightest. If you do know of me at all you know that if Justin and I HAD ever fought, not only wouldn't we be able to keep it secret, we'd be all too eager to share it with you. ...
Thing about making cartoons, sometimes they take way longer to create than you would guess (or hope). False starts. Potential story arcs that dead-end. Writer's block. Stuff happens. What's important (in the end) is that the shows are being made and people are working.
Happily, this is one of the Adult Swim shows that's union.