I love cute patterns, and sewing plush animals was also a fun passion of mine, but not actually creating them. The reason is simple. It's really hard.
Making a pattern that works takes a lot of time, first you need to draw up a completely custom pattern and try to make it work. Then since you have created something completely new sewing can really be a challenge.
Because I sew things, and I have been doing it for a long time and it stills gets unbelievably frustrating at times.
Because of that I have only ever tried making my own patterns a few times. And this with various success. They were never overly complicated and if they had been I would have thrown my hands in the air. Screamed. Then ran away from my machine.
But I haven't and I am glad.
So for me a good pattern is something to appreciate. If I find something that doesn't work, then Ican make the small alterations. But from scratch it is just too hard.
A friend of mine can do this, the patterns she makes for her children's toys are just amazing. And complicated.
I have tried to sew them but failed.
One of the reasons is because she has designed them herself. She knows where the gotchas are, and the other aspects that can cause you headaches. And this is just another reason why they are so complicated.
When you find a good patterns maker, support them, encourage them to keep going. Because for the majority of us, they are indespensible.