I understand a few of the team decisions for cottage living.

I think the llama was in large part added because it's the Sims mascot. And I'm sure people will at least be able to sell the wool, even if they don't have the knitting pack. The fact that you can use the wool for knitting if you have that pack is a nice bonus, though.

Edited to add: I just saw the speculation about using the wool to make thread. That makes total sense, now that I think of it. I hope it's true, so people without the knitting pack can use the wool they gather from the llamas.